Optical disk for high resolution and three-dimensional video recording, optical disk reproduction apparatus and optical disk recording apparatus

ABSTRACT

The present invention has an objective of providing an optical disk having a high resolution picture and a system for reproducing data on the optical disk, which are compatible with a conventional system for reproducing an ordinary resolution picture. A high resolution signal is divided into a main signal and a sub signal by picture division means and MPEG-encoded. The main signal and the sub signal are divided into frames each having 1 GOP or more. The resultant first interleave block  54  and second interleave block  55  are recorded alternately on an optical disk. A high resolution reproduction apparatus reproduced both the first and second interleave blocks, so that a high resolution picture is obtained. A non-high resolution reproduction apparatus reproduces only the first or second interleave block, so that an ordinary resolution picture.

This application is a continuation of U.S. patent application Ser. No.10/342,826 filed Jan. 15, 2003 now U.S. Pat. No. 7,317,868, which is acontinuation of U.S. application Ser. No. 09/319,476 filed Jun. 4, 1999,now U.S. Pat. No. 6,573,819, which is a §371 of InternationalApplication No. PCT/JP97/04429, filed Dec. 3, 1997.

TECHNICAL FIELD

The present invention relates to an optical disk having athree-dimensional (3D) picture and a high definition picture storedthereon, and an apparatus for recording data to or reproducing data fromthe optical disk.

BACKGROUND ART

A conventionally known optical disk having a 3D moving picture storedthereon is as shown in FIG. 10. An optical disk 201 has a picture forthe right eye (right-eye picture) stored in even fields 204, 204 a and204 b and a picture for the left eye (left-eye picture) stored in oddfields 203, 203 a and 203 b. The right-eye picture and the left-eyepicture are recorded alternately. When the data stored on the opticaldisk 201 is reproduced by an existing optical disk reproductionapparatus 205 shown in FIG. 11, a right-eye picture and a left-eyepicture appear on a TV screen 206 alternately every 1/60 second. Thenaked eye recognizes only a picture in which the right-eye picture andthe left-eye picture are overlapped. With 3D spectacles 207, in which ashutter for the right-eye picture and a shutter for the left-eye pictureare switched over every 1/60 second, a 3D picture is recognized. Asshown in FIG. 12, a right-eye picture and a left-eye picture are eachencoded alternately in every other field as an interlace signal in 1 GOPof an MPEG signal.

For high definition pictures, progressive systems referred to as 525Pand 720P have been studied.

A first problem of the conventional art will be described. When data ina conventional 3D optical disk is reproduced by an ordinary,conventional 2D reproduction apparatus, even a non-3D picture, i.e.,even a 2D picture is not output. Data in the 3D optical disk is onlyreproduced by a reproduction apparatus connected to a 3D display.Accordingly, it is required to create two types of optical disks, i.e.,a 3D optical disk and a 2D optical disk for the same contents. The sameis true with the high definition picture. In other words, theconventional 3D and high definition optical disks are not compatiblewith ordinary optical disks. A first objective of the present inventionis to provide a 3D or high definition optical disk which is compatiblewith ordinary optical disks, and a reproduction system for the 3D orhigh definition optical disk.

The term “compatibility” is clearly defined as similar to thecompatibility between monaural records and stereo records discussed inthe past. In other words, data in a novel 3D or high resolution diskaccording to the present invention is output as a “monaural” vision,i.e., as a 2D picture or an ordinary resolution picture by an existingreproduction apparatus developed for DVDs or the like, and is reproducedas a “stereo” vision, i.e., a 3D picture or a high resolution picture bythe novel reproduction apparatus according to the present invention.

A second problem of the conventional art concerns a synchronizationsystem. According to a conventional synchronization system, decodingstarts when decoding conditions for each compressed video signal areprovided. The conventional synchronization system has problems in that,for example, when the data becomes out of synchronization for somereason during reproduction, compensation is not performed; and thataudio data is not synchronized.

A second objective of the present invention is to provide a reproductionapparatus for reproducing a plurality of compressed video signals or aplurality of compressed audio signals in synchronization with oneanother and performing compensation when the data becomes out ofsynchronization during reproduction.

DISCLOSURE OF INVENTION

The present invention includes the following means to achieve theabove-described objectives.

An optical disk according to the present invention is obtained in thefollowing manner. Two moving pictures each having a frame rate of 30frames/sec. are input. A plurality of frames of each picture, whichcorrespond to 1 GOP or more of the disk, are set as a picture unit.These picture units of the two pictures are arranged on the optical diskalternately as interleave blocks. Each interleave block corresponds toone rotation or more. The two moving pictures can be, for example, apicture for the right eye and a picture for the left eye; or includesfield components of a progressive picture.

When such an optical disk is reproduced by an ordinary reproductionapparatus for two-dimensional (2D) display, an ordinary two-dimensionalis reproduced.

A reproduction apparatus for 3D and high definition pictures accordingto the present invention includes means for reproducing pictureidentification information from an optical disk, means for reproducing atwo-dimensional picture in a conventional process, means for reproducinga 3D or high definition picture, and means for outputting the 3D or highdefinition picture.

The present invention includes the following means to achieve the secondobjective.

A reproduction apparatus according to the present invention includesreference time signal generation means for generating a reference timesignal: and a plurality of picture extension/reproduction means having afunction of extending a compression video stream and controllingreproduction time of the extended video signal in accordance with thedifference between the reference time signal and the picturereproduction time information.

Another reproduction apparatus according to the present inventionincludes a plurality of picture extension/reproduction means having afunction of generating a reference time signal, extending a compressionvideo stream and controlling reproduction time of the extended videosignal in accordance with the difference between the reference timesignal and the picture reproduction time information. The reference timesignals in the plurality of picture extension/reproduction means arecorrected using identical information at substantially the same time.

Still another reproduction apparatus according to the present inventionincludes reference time signal generation means for generating areference time signal; and a plurality of audio extension/reproductionmeans having a function of extending a compression audio stream andcontrolling reproduction time of the extended audio signal in accordancewith the difference between the reference time signal and the audioreproduction time information.

Yet another reproduction apparatus according to the present inventioncontrols reproduction time by changing the frequency of the clock bywhich the audio extension/reproduction means performs extension andreproduction.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a recording apparatus in one exampleaccording to the present invention.

FIG. 2 is a timing diagram showing the relationship between an inputsignal and a recording signal in one example according to the presentinvention.

FIG. 3 is a top view of an optical disk showing the interleave blockarrangement in one example according to the present invention.

FIG. 4 is a view illustrating 3D picture arrangement information oneexample according to the present invention.

FIG. 5 is a view showing a reproduction apparatus in one exampleaccording to the present invention.

FIG. 6 is a timing diagram illustrating the relationship between arecorded signal and a picture output signal in a reproduction apparatusin one example according to the present invention.

FIG. 7 is a block diagram showing an MPEG decoder of a different systemof a reproduction apparatus in one example according to the presentinvention.

FIG. 8 is a timing diagram showing the relationship between a recordingsignal and an output signal when 2D reproduction is performed with areproduction apparatus in one example according to the presentinvention.

FIG. 9 is a block diagram showing a 2D reproduction apparatus in oneexample according to the present invention.

FIG. 10 is a top view showing data arrangement of a conventional opticaldisk having a 3D picture.

FIG. 11 is a block diagram showing a reproduction apparatus forreproducing a conventional optical disk having a 3D picture.

FIG. 12 is a timing diagram showing the relationship between a recordingsignal obtained by reproducing a conventional optical disk having a 3Dpicture and a picture output signal.

FIG. 13 is a timing diagram showing the relationship among a virtual 3Didentifier, an R output and an L output in one example according to thepresent invention.

FIG. 14 is a reproduction sequence view showing the difference of fpointer accessing in an ordinary picture reproduction mode and a 3Dreproduction mode in one example according to the present invention.

FIG. 15 is a flowchart (I) illustrating how a process of accessing apointer is changed in accordance with whether a 3D video signal isreproduced or not in one example according to the present invention.

FIG. 16 is a flowchart (II) illustrating how a process of accessing apointer is changed in accordance with whether a 3D video signal isreproduced or not in one example according to the present invention.

FIG. 17 is a flowchart showing how the manner of output is changed inaccordance with whether the signal to be reproduced is a 3D video signalor not by a 3D reproduction apparatus in one example according to thepresent invention.

FIG. 18 is a view showing a 3D picture identifier in a 3D picturelogical arrangement table in one example according to the presentinvention.

FIG. 19 is a flowchart showing a method for specifying the attribute ofeach chapter, cell and interleave block of a 3D picture based on a 3Dpicture identifier in the 3D picture logical arrangement table in oneexample according to the present invention.

FIG. 20 is a block diagram of a reproduction apparatus in an interlacepicture signal output mode in one example according to the presentinvention.

FIG. 21 is a block diagram of a reproduction apparatus in a progressivepicture signal output mode in one example according to the presentinvention.

FIG. 22 is a block diagram of a recording apparatus in a progressivepicture signal input mode in one example according to the presentinvention.

FIG. 23 is a view illustrating the principle of multiple angle videodata division multiplex system in one example according to the presentinvention.

FIG. 24 is a block diagram of a reproduction apparatus in a 3D picturesignal reproduction mode in one example according to the presentinvention.

FIG. 25 is a block diagram of a 4× reproduction apparatus in a 3Dprogressive picture signal reproduction mode in one example according tothe present invention.

FIG. 26 is a block diagram of a reproduction apparatus in a multi-streamprogressive picture signal reproduction mode in one example according tothe present invention.

FIG. 27 is a view illustrating a data structure of the entire opticaldisk in one example according to the present invention.

FIG. 28 is a view illustrating an inner structure of a volumeinformation file in FIG. 27 in one example according to the presentinvention.

FIG. 29 is a flowchart showing a detailed process for reproducing aprogram chain group by a system control section M1-9 in one exampleaccording to the present invention.

FIG. 30 is a block diagram showing a structure of a part of an AVsynchronization control 12-10, the part performing AV synchronization,in one example according to the present invention.

FIG. 31 is a timing diagram showing a data stream which is reproducedand output through a buffer of the decoder in one example according tothe present invention.

FIG. 32 is a view illustrating a method for reducing interlaceinterference by turning on or off a filter in one example according tothe present invention.

FIG. 33 is a view illustrating the principle of an encoding system usinga common motion detecting vector in one example according to the presentinvention.

FIG. 34 is a view illustrating a method for adjusting the timing forreproducing data from a DVD disk in one example according to the presentinvention.

FIG. 35 is a timing diagram showing reproduction of an interleave blockwhen one video stream is switched to another in one example according tothe present invention.

FIG. 36 is a view illustrating the principle of recording twoprogressive video signals after dividing them into interleave blocks inone example according to the present invention.

FIG. 37 is a flowchart showing a method for skipping a first dummy fieldof a VOB in one example according to the present invention.

FIG. 38 is a flowchart illustrating a process of STC switching forseamless connection in one example according to the present invention.

FIG. 39 is a block diagram of data decoding in one example according tothe present invention.

FIG. 40 is a view illustrating the principle of dividing a scope (wide)picture in a horizontal direction and recording the resultant signals asinterleave blocks in one example according to the present invention.

FIG. 41 is a view illustrating the principle of synthesizing a scope(wide) picture from an optical disk having the scope picture in adivided state and processing the synthesized picture with 3-2 transformin one example according to the present invention.

FIG. 42 is a structural view of a system stream and video data on anoptical disk in one example according to the present invention.

FIG. 43 is a flowchart for seamless connection in one example accordingto the present invention.

FIG. 44 is a view illustrating a method for dividing interpolationinformation in horizontal and vertical directions and recording theresultant signals in interleave blocks in one example according to thepresent invention.

FIG. 45 is a timing diagram of reproduction of progressive, 3D and widesignals with respect to the data amount in buffer in one exampleaccording to the present invention.

FIG. 46 is a structural view of a horizontal filter and a verticalfilter in one example according to the present invention.

FIG. 47 is a block diagram of a reproduction apparatus which shares acommon motion vector signal and color information in one exampleaccording to the present invention.

FIG. 48 is a view illustrating the principle of motion detection of aprogressive picture using a motion detection vector in one exampleaccording to the present invention.

FIG. 49 shows a signal format of a picture identifier in one exampleaccording to the present invention.

FIG. 50 shows contents of a vertical filter and a horizontal filter inone example according to the present invention.

FIG. 51 is a view illustrating the principle of dividing and recording a1050 interlace signal in one example according to the present invention.

FIG. 52 is an arrangement view for outputting a progressive signal, anNTSC signal and a HDTV signal in one example according to the presentinvention.

FIG. 53 is a view showing a progressive reproduction method forreproducing an interleave block while referring to a video presentationtime stamp in one example according to the present invention.

FIG. 54 is an arrangement view of an HDTV sub signal and an NTSC signalby simultaneous casting in one example according to the presentinvention.

FIG. 55 is a block diagram of a reproduction apparatus for an HDTV/NTSCdisk by simultaneous casting in one example according to the presentinvention.

FIG. 56 is a flowchart illustrating a method for controlling two buffersin one example according to the present invention.

FIG. 57 is a flowchart illustrating a method for performing AVsynchronization of a first decoder and a second decoder in one exampleaccording to the present invention.

FIG. 58 is a view illustrating the principle of an MADM system fordividing a signal into two in a horizontal direction in one exampleaccording to the present invention.

In FIG. 59, (a) is a view illustrating processing of an entirety of ahorizontal filter circuit in one example according to the presentinvention, and (b) is a view illustrating processing of each line of thehorizontal filter circuit in one example according to the presentinvention.

FIG. 60 is a block diagram of a system for dividing a scope-size pictureinto two in a horizontal direction and recording in the MADM system inone example according to the present invention.

FIG. 61 is a view illustrating the principle of a provider definedstream multiplex system (vertical division) in one example according tothe present invention.

FIG. 62 is a view illustrating the principle of a provider definedstream multiplex system (horizontal division) in one example accordingto the present invention.

FIG. 63 shows a signal format of provider defined stream multiplexsystem in one example according to the present invention.

FIG. 64 is a block structural view of an optical disk reproductionapparatus in one example according to the present invention.

FIG. 65 is a structural view of a video decoder in one example accordingto the present invention.

FIG. 66 shows a data structure of an optical disk in one exampleaccording to the present invention.

FIG. 67 is a timing diagram of video reproduction in one exampleaccording to the present invention.

FIG. 68 is a block structural view of an optical disk reproductionapparatus in one example according to the present invention.

FIG. 69 is a structural view of an audio decoder in one exampleaccording to the present invention.

FIG. 70 shows a data structure of an optical disk in one exampleaccording to the present invention.

FIG. 71 is a timing diagram of audio and video reproduction in oneexample according to the present invention.

FIG. 72 shows an optical disk reproduction apparatus in one exampleaccording to the present invention.

FIG. 73 is a structural view of a video decoder in one example accordingto the present invention.

FIG. 74 is a timing diagram of video reproduction in one exampleaccording to the present invention.

FIG. 75 is a block structural view of an optical disk reproductionapparatus in one example according to the present invention.

FIG. 76 is a structural view of a video decoder in one example accordingto the present invention.

FIG. 77 is a structural view of a video decoder in one example accordingto the present invention.

FIG. 78 is a structural view of a video decoder in one example accordingto the present invention.

FIG. 79 is a block structural view of an optical disk reproductionapparatus in one example according to the present invention.

FIG. 80 is a structural view of an audio decoder in one exampleaccording to the present invention.

FIG. 81 shows a data structure of an optical disk in one exampleaccording to the present invention.

FIG. 82 is a timing diagram of audio and video reproduction in oneexample according to the present invention.

FIG. 83 is a timing diagram of operation frequencies of audio and videoreproduction in one example according to the present invention.

FIG. 84 is a timing diagram of operation frequencies of audio and videoreproduction in one example according to the present invention.

FIG. 85 is an IP structural view of an MADM stream in one exampleaccording to the present invention.

FIG. 86 shows a method for preventing a conventional reproductionapparatus from outputting a sub picture signal in one example accordingto the present invention.

FIG. 87 shows simulation calculation results showing a buffer amountrequired for simultaneous reproduction in one example according to thepresent invention.

FIG. 88 is an arrangement view of continuous blocks and interleaveblocks in one example according to the present invention.

FIG. 89 is an arrangement view of interleave blocks in one exampleaccording to the present invention.

FIG. 90 is a block diagram of multiple (2) screen in one exampleaccording to the present invention.

FIG. 91 is a view illustrating the principle of dividing a highresolution video signal in a horizontal direction to obtain two streams,recording the streams, synthesizing the two streams to reproduce thehigh resolution video signal (luminance signal) in the first exampleaccording to the present invention.

FIG. 92 is a view illustrating the principle of dividing a highresolution video signal in a horizontal direction to obtain two streams,recording the streams, synthesizing the two streams to reproduce thehigh resolution video signal (color signal) in the first exampleaccording to the present invention.

FIG. 93 is a flowchart illustrating the compatibility when an MADM diskin the first example according to the present invention is reproduced bya conventional reproduction apparatus.

FIG. 94 is a flowchart illustrating an operation of reproducing an MADMdisk in the first example according to the present invention by an MADMreproduction apparatus.

In FIG. 95, (a) is a view illustrating an accessing process using apointer of first reproduction information when an MADM disk in the firstexample according to the present invention is reproduced by aconventional reproduction apparatus, and (b) is a view illustrating anaccessing process using second reproduction information when an MADMdisk in the first example according to the present invention isreproduced by an MADM reproduction apparatus.

FIG. 96 is a block diagram of a reproduction apparatus for synthesizingtwo streams in the first example according to the present invention.

FIG. 97 is a block diagram of a system for reproducing two streamsobtained by being divided on a frame-by-frame basis and synthesizing thestreams in a time axis in the first example according to the presentinvention.

FIG. 98 is a block diagram of a recording apparatus and a reproductionapparatus for dividing a progressive video signal into two streams andsynthesizing the signals into the progressive video signal in the firstexample according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode of the present invention will be described with referenceto the figures.

In this specification, a recording and reproduction system forsimultaneously reproducing a plurality of streams according to thepresent invention will be referred to as an “MADM” system.

In the first example of the present invention, a method for recordingand reproducing a 3D picture and a high definition picture will be firstdescribed, and then a method for realizing the high definition picturewill be described, both as applications of the MADM system according tothe present invention. In the second through eighth examples, practicalmethods for synchronization used for reproducing data according to theMADM system will be described.

Example 1

According to the present invention, a 3D picture and a wide screenpicture are recorded in the state where the picture is divided into twopictures of a right-eye picture and a left-eye picture, or divided intotwo screen pictures separated from each other along a horizontal line.These two pictures are field pictures starting from an odd line, and asignal representing such a field picture is referred to as an Odd Firstsignal. A progressive picture is recorded as being divided into twoscreen pictures separated from each other along a vertical line. Thesetwo screen pictures are represented by a field signal starting from anodd line and a field signal starting from an even line. These signalsare referred to as an Odd First signal and an Even First signal. In thisspecification, a recording unit of picture information of 1 GOP or morewhich has been processed with interleaving is referred to as aninterleave block or a frame group. The system according to the presentinvention is referred to as a multiple angle video data divisionmultiplex (MADM) system.

FIG. 1 is a block diagram of an MADM system recording apparatus 2 for anoptical disk according to the present invention. A progressive signaland a 3D signal can both be recorded. A right-eye signal of the 3Dpicture is referred to as an R-TV signal, and a left-eye signal isreferred to as an L-TV signal. The R-TV signal and the L-TV signal arecompressed into MPEG signals by MPEG encoders 3 a and 3 b. As a result,an R-MPEG signal and an L-MPEG signal as shown in part (2) of FIG. 2 areobtained. These signals are processed with interleaving by an interleavecircuit 4, so that an R-frame group 6 including R-frames 5 correspondingto 1 GOP or more of the R-MPEG signal and an L-frame group 8 includingL-frames 7 corresponding to 1 GOP or more of the L-MPEG signal arealternately arranged as shown in part (3) of FIG. 2. The recording unitis referred to as an interleave block, and may also be referred to as aframe group in this specification. The R-frame group 6 and the L-framegroup 8 include an identical number of frames having an identical timeperiod, so that the right-eye signal and the left-eye signal aresynchronized with each other when being reproduced. The frame group isalso referred to as a picture data unit. One picture data unitcorresponds to 0.4 to 1 second. A rotation speed of a DVD is 1440 rpm,i.e., 24 Hz along the innermost track. Accordingly, an interleave blockcorresponds to one or more rotations or further, 10 to 20 rotations asshown in part (4) of FIG. 2. Returning to FIG. 1, address information isoutput from an address circuit 13. Progressive/3D picture arrangementinformation is output from a progressive/3D picture arrangementinformation output section 10. These pieces of information are recordedon the optical disk by a recording circuit 9. The progressive/3D picturearrangement information includes an identifier which indicates whetheror not a progressive or 3D picture is present on the optical disk, or aprogressive/3D picture arrangement table 14 shown in FIG. 4. As shown inFIG. 4, a TEXTDT file 83 includes, for each VTS, 3D pictures for theright and left eyes and angle numbers and cell numbers in which theprogressive signal is located. Since a PGC file of each VTS includes astarting address and a termination address of each cell, the startingaddress and the termination address of each cell are included in theprogressive/3D picture arrangement information. Based on the arrangementinformation and identification information, the reproduction apparatusoutputs a progressive picture or a 3D picture correctly as progressiveoutputs or R and L outputs. When ordinary pictures of different contentsfrom each other are output as R and L outputs in error, the user willfeel uncomfortable since the pictures for the right eye and the left eyeare not related to each other. The progressive/3D picture arrangementinformation or progressive/3D picture identifier have an effect ofavoiding the output of such unpleasant pictures. The manner of using theprogressive/3D picture arrangement information and progressive/3Dpicture identifier will be described in detail later together with adescription of the reproduction apparatus.

In the recording apparatus shown in FIG. 1, a 525P or other progressivesignal can be recorded with multiple angles. Specifically, a progressivesignal is divided into a sum component and a difference component by adivision section 38, thereby creating two interlace signals. The twointerlace signals are encoded by the two MPEG decoders 3 a and 3 b. Inthis case, a VPTS which is synchronized with an APTS of an audio signalis provided to a first MPEG signal and a second MPEG signal by a VPTSprovision section 81. Such provision will be described in detail later.

A specific method for creating 3D picture arrangement information willbe described. A DVD-format optical disk has files of a directory ortable of contents stored in a standardized manner in a recordingstarting area thereof. However, these files do not include anydescription on 3D pictures. Accordingly, a 3D picture logicalarrangement file 53 including a 3D/PG picture logical arrangement tableshown in FIG. 18 is provided, so that a reproduction apparatusconforming to 3D reproduction reads the file. An ordinary 2Dreproduction apparatus cannot read the 3D/PG picture logical arrangementfile 53 but provides no problem since such an ordinary 2D reproductionapparatus does not reproduce a 3D picture.

Hereinafter, the table in FIG. 18 will be described. DVD videoinformation includes a three-layer logical hierarchy. The three layersare a video title set (VTS) layer representing a movie or other work, apart of video title (PVT) layer representing a chapter in the title, anda cell (Cell) layer representing a stream in the chapter.

The arrangement of 3D pictures in each layer will be described. “000”indicates that there is no 3D or progressive cell; “110” indicates thatall cells are 3D cells; and “001” indicates that there are 3D cells andnon-3D cells.

In FIG. 18, regarding the VTS layer, the status of title 1 is “001”;i.e., the VTS layer of title 1 includes both 3D and ordinary cells. Thestatus of title 2 is “110”; i.e., all the cells in the VTS layer oftitle 2 are 3D cells. The status of title 3 is “000”; i.e., there are no3D cells in the VTS layer of title 3. Accordingly, information on 3Dpictures is not necessary regarding the lower layers of titles 2 and 3.

Regarding PVT layer of title 1, the status of chapter 2 is “000”; i.e.,there are no 3D cells in the PVT layer of chapter 2. The status ofchapter 3 is “110”; i.e., all the cells are 3D cells in the PVT layer ofchapter 3. The status of chapter 1 is “001”; i.e., there are both 3Dcells and the ordinary cells in the PVT layer of chapter 1. Regardingthe cell layer of chapter 1, cells 1 and 2 correspond to R and L data ofa first stream. Cells 3 and 4 correspond to R and L data of a secondstream. In cells 5 and 6, ordinary pictures are recorded. In theembodiment where the 3D/PG picture logical arrangement file 53 isseparately recorded on the optical disk in this manner, the conventionalfile is not altered. Accordingly, compatibility between the 3D/PGpictures and the ordinary pictures is realized. The logical informationreveals all the physical information on the optical disk. Accordingly, amalfunction of displaying ordinary pictures of two different contentsfor the right eye and the left eye is prevented. Moreover, the 3Dpicture can be appropriately reproduced and decoded so that R and L dataare provided to the right eye and the left eye from the correct outputsections.

With reference to the flowchart of FIG. 19, a process for determiningwhether or not each cell includes a 3D or progressive picture based onthe 3D/PG picture logical arrangement table 52 will be described. Instep 51 a, the 3D/PG picture logical arrangement table 52 is read from afirst recording area of the optical disk. In step 51 b, the VTS layer oftitle n as shown in FIG. 18 is checked. When the status of the VTS layeris “000”, it is determined that no 3D or progressive cell is includedand thus 3D processing is not performed. When VTS=110 in step 51 c, allthe cells are processed as 3D cells in step 51 d. In step 51 e, oddcells are processed as including a left-eye picture and even cells areprocessed as including a right-eye picture. In step 51 f, a menu screenis caused to indicate that all the cells in title n are 3D cells. WhenVTS=001 in step 51 g, the arrangement information of chapter n of thelower layer is checked in step 51 i. When PVT=000 in step 51 j, it isdetermined that chapter n include no 3D or PG cells in step 51 k. WhenPVT=110 in step 51 m, it is determined that all the cells in chapter nare 3D cells in step 51 n. Then, the processing goes to step 51 d, wherethe menu screen indicates that the all the cells in chapter n are 3Dcells. When PVT=001 in step 51 p, each of the cells in that chapter ischecked. When Cell=000 in step 51 s regarding one cell, it is determinedthat the cell is not a 3D cell and the processing goes back to step 51q. When Cell=m−R in step 51 u, it is determined that the cellcorresponds to R data of stream m in step 51 v. When Cell=m−L in step 51w, it is determined that the cell corresponds to L data of stream m instep 51 x. Then, the next cell is checked in step 51 q.

In the embodiment where the 3D/PG picture logical arrangement table 52is additionally recorded in this manner, it is effectively determinedwhether or not each of all the video titles, chapters and cells includes3D data, PG data or neither of such data.

This will be described with respect to the top view of the optical diskin FIG. 3. An optical disk 1 has one spiral track formed therein. TheR-frame group 6 is recorded on a plurality of R tracks 11, 11 a and 11b. In actuality, the R-frame group 6 is recorded on 5 to 24 tracks. TheL-frame group 8 is recorded on L tracks 12, 12 a and 12 b, and the nextR-frame group 6 a is recorded on R tracks 11 c, 11 d and 11 e.

Hereinafter, a reproduction operation will be described with referenceto the block diagram of the 3D reproduction apparatus according to thepresent invention in FIG. 5 and the timing diagram in FIG. 6. When asignal from the optical disk 1 is reproduced by an optical head 15 andan optical signal reproduction circuit 24 and a 3D picture identifier isdetected by a 3D picture arrangement information reproduction section26, or when picture data which has been determined to have a 3D picturebased on a 3D picture arrangement table 14 shown in FIG. 4 is to bereproduced and an input section 19 or the like issues an instruction tooutput a 3D picture; a switch section 27 is controlled so that an Rsignal and an L signal are output from an R output section 29 and an Loutput section 30 and so that the R and L signals are output alternatelyon a field-by-field basis from an RL mixture circuit 28. The control ofthe switch section 27 is performed simultaneously with the processing ofthe 3D picture.

With reference to FIGS. 5 and 6, an operation for reproducing a 3Dpicture will be described. As described with reference to part (3) ofFIG. 2, the R-frame group 6 and the L-frame group 8 are alternatelyrecorded on the optical disk. The R-frame group 6 and the L-frame group8 each include frames corresponding to n GOPs, where n is an integer ofone or more. FIG. 85 represents such a state in detail. Two (right andleft) streams are recorded on the disk alternately. Each stream includesintra-frame encoded frame data represented as I and inter-frame encodedframe data represented as B or P, and is divided into interleave unitswith the intra-frame encoded frame as a disconnection point.

In FIG. 6, part (1) shows the entirety of the disk, and part (2) shows apart thereof. An output signal from an optical signal reproductioncircuit 24 in FIG. 5 is represented as part (2) of FIG. 6. The signal isdivided into an R signal and an L signal by a switch section 25, and thetime axes of the R signal and the L signal are matched to an originaltime axis respectively by a first buffer circuit 23 a and a secondbuffer circuit 23 b. By this operation, input signals, shown in part (4)of FIG. 6, to be input to R- and L-MPEG decoders are obtained. Thesignals are respectively processed by MPEG decoders 16 a and 16 b inFIG. 5. Thus, R and L output signals which are synchronized with eachother as shown in parts (6) and (7) of FIG. 6 are sent to a pictureoutput section 31. An audio signal is extended by an audio outputsection 32 and then output.

Since the two (R and L) signals are output simultaneously in thismanner, a flickerless picture is obtained by sending a 60 fps(frames/sec.) signal from each of the R output section 29 and the Loutput section 30 to the 3D TV having two (R and L) outputs. In theembodiment where an RL mixture signal having 60 fields/sec. is sent fromthe RL mixture circuit 28, a 3D picture can be viewed with an ordinaryTV and 3D spectacles, although the picture flickers. In the embodimentwhere an RL mixture signal having 120 fields/sec. is output, aflickerless 3D picture can be viewed with a 2× scan TV and 3Dspectacles. In the case where a 3D picture is not being output as a 3Dpicture, a signal is added by a “3D” display signal output section 33 sothat the TV screen display a symbol indicating “3D”. Then, the user isnotified that he/she is viewing 3D software in a 2D mode and is urged toswitch to the 3D output mode. In the embodiment where a 3D controlsignal generated by a 3D spectacle control signal generation section 33a for switching right and left shutters of the 3D spectacles is detectedfrom a frame synchronization signal for a decoding signal or from the RLmixture circuit 28 and output to an external device, a synchronizationsignal for the 3D spectacles is obtained.

When a line memory 28 c of an n-screen synthesis section 28 b in FIG. 90is used, n pieces of pictures (e.g., two pictures) are output on a TVscreen as one NTSC signal picture in which the two pictures aresynthesized. Therefore, two angles can be viewed with an ordinary TV. Aconventional 1× reproduction apparatus inconveniently displays only oneangle at one time out of multiple angles. The present invention allowstwo streams to be reproduced simultaneously with a 2× reproductionapparatus and the MADM reproduction system, and also allows two screensto be displayed simultaneously. Accordingly, it is not necessary toswitch the multiple angles.

As shown in FIG. 90 in detail, when the line memory 28 c of the n-screensynthesis section 28 b is used, a two-picture display 28 f of twopictures A and B having the same size is obtained. Since a line memoryhas a simple structure and is integrated into an IC, the n-screenpicture display is obtained with a simple structure. When a frame memory28 d is used, a two-picture display 28 g of two pictures havingdifferent sizes is obtained by a zoom signal from a zoom signalgeneration section 28 e. Since the user can arbitrarily set the size byremote control, the TV picture can be advantageously viewed at anoptimum size.

In the block diagram in FIG. 5, two MPEG decoders are used. Thestructure is simplified by the circuit configuration shown in FIG. 7.The first MPEG signal and the second MPEG signal are synthesized intoone MPEG signal by a synthesis section 36, and a 2× clock is generatedby a 2× clock generation section 37. A 2× calculation is performed by a2× clock-type MPEG decoder 16 c, and the data is extended and output asR and L video signals through a division section 38. Such a circuitconfiguration advantageously limits an increase in the cost since it isonly necessary to add a 16 MB SD-RAM to a memory 39 of an existing 2Dreproduction apparatus.

With reference to FIG. 7, synchronous reproduction of two streams whichis important in decoding 3D picture data and progressive picture datawill be described. First, it is necessary to adjust vertical andhorizontal synchronization of two streams within a single line. In orderto do this, a first MPEG decoder 16 a and a second MPEG decoder 16 b arestarted substantially simultaneously by a vertical/horizontalsynchronization control section 85 c to synchronize the decoders 16 aand 16 b. Then, it is necessary that the outputs from the two decodersshould be pictures having an identical VPTS. This will be described withreference to the flowchart in FIG. 57 and FIG. 7. In step 241 a, thesynchronization of a first decoder and a second decoder is cancelled. Instep 241 b, the decoders are synchronized with each other vertically andhorizontally. In step 241 c, an APTS of an audio signal is read, and theAPTS value is set as an initial value of an STC of the first decoder andan STC of the second decoder. In step 241 e, processing of the firstdecoder is started. In step 241 f, it is checked whether or not a firstVPTS has reached the initial value. If yes, decoding is started in step241 g. In step 241 h, a processing delay time period of the firstdecoder is calculated, and the VPTS of the decoder output is adjusted sothat the APTS and the VPTS are synchronized with each other. Since thesecond decoder is processed in the same manner, the picture from thefirst decoder and the picture from the second decoder are synchronizedwith each other. Thus, the decoder outputs, i.e., the first MPEG signaland the second MPEG signal are synchronized within one line. Then, thesynchronization on a dot-by-dot basis is obtained by a video signalsynchronization section 36 a of the synthesis section 36. An originalprogressive picture is obtained even by a sum calculation. As shown inFIG. 5, in the case where an APTS 84 is read by the audio decoder 16 cand an identical APTS is set in registers 39 a and 39 b of the STCs ofthe two MPEG decoders 16 a and 16 b, an audio stream and the two videostream are automatically synchronized with one another.

In the present invention, when the buffer circuits 23 a and 23 bunderflow, either one of the pictures is disconnected, as a result ofwhich a disturbed progressive picture is output. In order to avoid this,the buffering amounts of the two buffer circuits are controlled by abuffer amount control section 23 c as shown in FIG. 5. This operation isillustrated in the flowchart shown in FIG. 56. First, in step 240 a, amaximum interleave value among the NAVI information of each disk isread, and a maximum value of 1 ILB in one main interleave block is set.The maximum value is usually 512 sectors, i.e., about 1 MB. When themaximum value is set below 1 MB by a specific format, that value is setas the maximum value. Next, when an instruction to simultaneouslyreproduce the main and sub interleave blocks is issued in step 240 b, ifthe buffering amount of the first buffer circuit 23 a is 1 ILB or lessin step 240 c, reproduction is performed from the main interleave block,and an instruction to transfer the data to the first buffer circuit 23 ais issued. Then, the processing goes back to steps 240 b and 240 a. Thetransfer is stopped in step 240 d when the buffering amount of the firstbuffer circuit exceeds 1ILB. Since the data in the buffer circuit 23 abecomes 1ILB or more in this manner, underflow is prevented.

In step 240 f, a maximum value of a sub interleave block of 1 ILB-Sub isset in the buffer circuit 23 b. Simultaneous reproduction is performedin step 240 g. When the data in the second buffer circuit 23 b is ½ILB-Sub or less, data is read into the buffer circuit in step 240 i.When the data is more than ½ ILB-Sub in step 240 i, the reading isstopped in step 240 i.

As shown in part (4) of FIG. 45, the data amount of ½ ILB is sufficientin the second buffer circuit. Accordingly, the buffering amount can bereduced to half. The buffer control in FIG. 56 eliminates the underflowof the buffer circuits, thus reducing disturbance in the synthesizedpicture during reproduction.

Next, a process for reproducing only an R signal by 1× rotation of theoptical disk will be described. The standard rotation speed of a DVDreproduction apparatus is referred to as “1×”, and the speed twice thestandard rotation speed is referred to as “2×”. Since it is notnecessary to rotate the motor at 2×, a 1× instruction is sent from acontrol section 21 to a rotation speed alternation circuit 35 to reducethe rotation speed. A process for reproducing only an R signal at 1×rotation from an optical disk storing the R signal and an L signal willbe described with reference to the timing diagram in FIG. 8. Asdescribed with reference to parts (1) and (2) of FIG. 6, the opticaldisk according to the present invention has the R-frame group 6 and theL-frame group 8 alternately recorded. This is shown in parts (1) and (2)of FIG. 8.

A comparison between the signal shown in parts (1) and (2) of FIG. 8 anda signal shown in part (3) of FIG. 8 corresponding to one rotation ofthe disk indicates that the optical disk rotates 5 to 20 times while oneframe group is reproduced. A track jump of the optical head from theR-frame group 6 to the next R-frame group 6 a requires several tens ofmilliseconds. Where the wait time period is one rotation, which is themaximum, the data in the R-frame group 6 a can be reproduced within tworotations. This is shown in parts (4) and (5) of FIG. 8, which aretiming diagrams of the reproduction signal and the signal correspondingto one rotation of the disk. The time axis of the reproduction signal inpart (4) of FIG. 8 is adjusted by the buffer circuit 23 a in FIG. 5, andan MPEG signal having continuous R frames as shown in part (6) of FIG. 8is output from the buffer circuit 23 a. This signal is extended to be anR video signal as shown in part (7) of FIG. 8 by the MPEG decoder 16 a.By selecting a different channel in the same manner as the case of the Rsignal, a 2D signal of the L channel is obtained. According to thepresent invention, the R or L channel is assigned to a frame group of 1GOP or more and the frame group is recorded continuously over aplurality of tracks. Thus, even when a 3D optical disk is reproduced bya 1× reproduction apparatus, a 2D output of only the R channel isobtained.

As can be appreciated from this, as shown in the block diagram of FIG.9, a reproduction apparatus specifically for 2D display is obtained byaltering the structure of the 3D reproduction apparatus in FIG. 5 sothat there is only one buffer circuit 23 in lieu of two, one MPEGdecoder 16 in lieu of two, and one picture output section 17. Such a 2Dreproduction apparatus 40 includes the 3D picture arrangementinformation reproduction section 26, and therefore, reproduces a 3Dpicture identifier and arrangement information of the 3D optical disk 1.Accordingly, when the data in the optical disk 1 is reproduced by the 2Dreproduction apparatus, data in either one out of the R and L channelsis output. Since the R and L channels correspond to an identicalpicture, it is a waste of time to output the pictures in the R and Lchannels by switching the channels by a channel selection section 20.According to the present invention, a 3D channel output control section41 restricts data to be output from only either channel, for example,the R channel, using the 3D picture identifier. Thus, data in only the Ror L channel of identical video contents is output, avoiding thesituation in which the user selects an unnecessary channel.

When a 3D picture is provided, the “3D” display signal output section 23displays the symbol “3D” on the screen or a display section 42 of thereproduction apparatus. Therefore, the user can recognize that thepicture is a 3D picture. The optical disk according to the presentinvention provides both 2D and 3D pictures when reproduced by the 3Dreproduction apparatus 43 in FIG. 5 and a 2D picture when reproduced bythe 2D reproduction apparatus in FIG. 9. In this manner, thecompatibility between the 2D reproduction apparatuses and 3Dreproduction apparatuses realized.

Now, returning to the 3D reproduction apparatus, use and effect of a 3Dpicture identifier will be described.

FIG. 13 is a timing diagram of a 3D picture identifier and an outputsignal. One interleave block is defined as a time unit “t”. In parts (3)through (6) of FIG. 13, a delay time period of 1t is generated althoughnot shown. As shown in part (1) of FIG. 13, the state of the 3D pictureidentifier is changed from “1” to “0” at t=t7. As shown in part (2) ofFIG. 13, the R-frame groups 6, 6 a and 6 b and the L-frame groups 8, 8 aand 8 b of a 3D picture are recorded from t1 through t7. From t7 throught11, pictures A and B of different contents are recorded. In moredetail, first-frame groups 44 and 44 a of picture A and second-framegroups 45 and 45 a of picture B are recorded. Since the DVD format doesnot define 3D pictures, a 3D picture identifier is not included in thedata or directory information of the disk. Accordingly, a 3D picturearrangement information file needs to be read when the optical disk isstarted. As shown in parts (3) and (4) of FIG. 13, from t1 through t7,data in first time domains 46, 46 a and 46 b can be output to the Rchannel, and data in the second time domains 47, 47 a and 47 b can beoutput to the L channel. After t=t7, no 3D picture identifier isavailable. Accordingly, data in, for example, first time domains 46 cand 46 d is output to both the R and L channels. As shown in parts (5)and (6) of FIG. 13, a different output system is adopted for a mixtureoutput. From t1 through t7 when the 3D picture identifier is “1”, evenfield signals 48 and 48 a and odd field signals 49 and 49 a arealternately output from one output at a field frequency of 60 Hz or 120Hz. In more detail, data in the first time domains 46 and 46 a is outputas the even field signals, and data in the second time domains 47 and 47a is output as the odd field signals.

After t=t7 when the 3D picture identifier is not available, data in thefirst time domains 46 c and 46 d is output as both the even fieldsignals 48 d and 48 e and the odd field signals 49 d and 49 e.

As described above, the manner of outputting signals to the 3D displayis changed in accordance with whether or not the 3D picture arrangementinformation indicates the absence of the 3D picture. In this manner, itis prevented that pictures of different contents from each other arepresented for the right and left eyes of the user. Without such afunction, the following inconvenience occurs. In the case where thefirst time domain and the second time domain of the optical disk startto include different contents from each other while the user is viewinga right-eye picture and a left-eye picture of the same contents, apicture of content A is presented to the right eye and a picture ofcontent B is presented to the left eye. Such an abnormality makes theuser feel uncomfortable.

With reference to the flowchart of FIG. 17, the above-described processwill be described in detail. In step 50 a, an optical disk is mounted.In step 50 b, a file of a list of contents in the optical disk is read.The file does not include a 3D picture identifier. In step 50 c, a 3Dpicture arrangement information is read from a TXTDT file of the disk.

In step 50 d, the list of contents is displayed based on the 3D picturearrangement information. At this point, “3D” is displayed for each ofthe contents on the menu screen, so that the user can recognize that 3Dcontents are available. This information can be in one area of theoptical disk or included in navigation information provided on adata-by-data basis.

In step 50 e, data in a specific address is reproduced. In step 50 f, itis determined whether or not the data is 3D data with reference to the3D picture arrangement information. If yes, in step 50 g, signals aredecoded. For example, an R signal in the first time domain 46 and an Lsignal in the second time domain 47 are decoded. The data in the firsttime domain 46 is output as the right-eye picture, and the data in thesecond time domain 47 is output as the left-eye picture. The picturesare synchronized. For reproduction of the next data, the processing goesback to steps 50 e and 50 f, where it is determined whether or not thepicture is a 3D picture. If no, the processing goes to step 50 h, wherethe data in either one of the first time domain 46 or the second timedomain 47 is output as both the right-eye picture and the left-eyepicture. In other words, the same picture is output for the right eyeand the left eye. Thus, pictures of different contents are preventedfrom being output to the right eye and the left eye.

According to the present invention, an ordinary picture and a 3D pictureboth of the interleave block system are reproduced in different manners.This will be described, herein after.

With reference to FIG. 14, part (1) shows data recorded on the opticaldisk. A first interleave block 56 includes data A1 and a leading addressa5 of the first interleave block 56 to be accessed next, i.e., the nextpointer 60. Accordingly, as shown in part (2) in FIG. 14, whenreproduction of the first interleave block 56 is terminated, only theaddress of the pointer 60 a needs to be accessed. Thus, the optical headperforms a track jump to access the next first interleave block 56 awithin 100 ms and reproduces data A2. Data A3 is reproduced in samemanner. In this manner, contents A1 through A3 are reproduced.

Part (3) of FIG. 14 is related to an optical disk having 3D pictures forR and L outputs. The optical disk includes the same pointer 60 in orderto have the same format as in part (1) of FIG. 14 for compatibility.Accordingly, a 3D picture is not reproduced unless the pointer 60 isignored.

A 3D picture identifier 61 of each cell is defined based on the 3Dpicture logical arrangement table. Accordingly, 3D picture identifiers61 of interleave blocks 54, 55, 56 and 57 are logically defined. This isshown in part (3) of FIG. 14. The pointer cannot be used as it is inorder to reproduce data R1 and L1 and then reproduce data R2 and L1after a track jump. Specifically, when reproduction of the R interleaveblock 54 is completed, the address of the pointer a5 is not accessed.Rather, after reproduction of the next L interleave block 55, theoptical head performs a track jump to the pointer a5 of the R interleaveblock. In this case, the pointer 60 b of the L interleave block 55 isignored. For reproducing an interleave block where the 3D pictureidentifier is available, it is advantageous to change the manner ofaccessing the pointer address from the case of the reproduction of anordinary picture, the advantage being that R and L pictures arecontinuously reproduced as shown in part (4) of FIG. 14.

With reference to flowcharts in FIGS. 15 and 16, a process of changingthe manner of accessing the pointer address when reproducing aninterleave block using a 3D picture arrangement information will bedescribed.

In step 62 a, an access instruction to an address of a specific cell isissued. In step 62 b, it is determined whether or not the picture to beaccessed is 3D with reference to the 3D picture arrangement information.If the picture is determined not to be 3D in step 62 c, the processinggoes to step 62 t, where the picture is processed as an ordinarypicture. If the picture is determined to be 3D in step 62 c, theprocessing goes to step 62 d, where it is checked whether or not theuser intends to reproduce the picture as a 3D picture. If no, the “3D”mark is displayed on the screen and the processing goes to step 62 t.

If yes in step 62 d, the 3D picture arrangement information is read instep 62 e, and the locations of the R and L interleave blocks arecalculated based on, for example, the chapter number, R cell number andL cell number. In step 62 g, the n'th R interleave block is reproduced.In step 62 h, the pointers recorded in the R interleave block and the Linterleave block are read and stored in the pointer memory. In step 62i, the previous pointer (i.e., the (n−1)th pointer AL (n)) is read fromthe pointer memory. In step 62 j, it is checked whether or not pointersAL(n) and AR(n) are continuous with each other. If no, a jump to theaddress AL(n) is performed in step 62 k.

As shown in FIG. 16, in step 62 m, the n'th L interleave block isreproduced. In step 62 n, the first VPTS and the second VPTS are outputin synchronization using the pointer AR(n+1). In step 63 g, the firstVPTS and the second VPTS are synchronized using APTS of the maininterleave block. If in step 63 h, the signal is found to be a PG, i.e.,progressive signal, in step 63 i, a sum and a difference of the twodecoding output signals are found to and a vertical synthesis isperformed. Thus, a picture having an improved vertical resolution suchas a 525P picture is obtained.

If the signal is found to be wide 525P(i) in step 63 j, a sum and adifference of the two decoding output signals are found and a horizontalsynthesis is performed. Thus, a picture having an improved horizontalresolution such as a wide 525P(i) picture of, for example, 1440×480pixels is obtained. In step 62 p, it is checked whether or not thereproduction of all the streams is completed. In step 62 q, it ischecked whether or not the n'th L interleave block and the (n+1) th Rinterleave block are recorded continuously with each other. If no, atrack jump to the AR(n+1) is performed in step 62 r and the processinggoes back to step 62 f. If yes in step 62 q, the processing directlygoes back to step 62 f.

In the case where the “3D” mark mentioned regarding step 62 t is notdisplayed on the screen, the starting address A(1) of cell h is accessedand the first interleave block is reproduced. Then, in step 62 u, then'th interleave blocks of address A(n) are sequentially reproduced. Instep 62 v, the pointer address A(n+1) for accessing the next interleaveblock by jumping is read. In step 62 w, it is checked whether or not thereproduction of all the data is completed. If yes, the processing goesback to step 62 a. If no, in step 62 x, it is checked whether or notA(n) and A(n+1) are continuous with each other. If yes, the processinggoes back to the step before step 62 u without jumping. If no, in step62 y, a jump to the address A(n+1) is performed.

FIG. 20 is a block diagram of a reproduction apparatus 65 according tothe present invention. An operation of the reproduction apparatus 65 forreproducing 2× progressive pictures, wide screen pictures and 720Ppictures will be described. A signal reproduced from an optical disk 1is divided by a division section 8 into a first interleave block 66 anda second interleave block 67 each including frames corresponding to 1GOP or more. The blocks are respectively MPEG-extended into frame videosignals 70 a and 70 b each having 30 frames/sec. The video signal 70 ais divided by a field division section 71 a into an odd field signals 72a and 73 a. The video signal 70 b is divided by a field division section71 b into an odd field signals 72 b and 73 b. Thus, 2-ch NTSC interlacesignals 74 a and 74 b are output. The wide screen picture reproduced bythe reproduction apparatus in FIG. 20 will be described later.

With reference to FIG. 22, an encoding operation of a progressive videosignal will be described. Progressive video signals 75 a and 75 b areinput at time t1 and t2, and divided by a division section 38 into anOdd First interlace signal 244 and an Even First interlace signal 245.Where the n'th line (e.g., 1st line) of the interlace signal 244 islabeled as “An” and the n'th line (e.g., 2nd line) of the interlacesignal 245 is labeled as “Bn”, a vertical filter 142 performs a sumcalculation, i.e., ½(An+Bn), thus obtaining a low frequency component.In other words, a function of an interlace interference removal filter141 is performed. In the case where the resultant component isreproduced from only one angle by a conventional reproduction apparatus,an NTSC signal with no interlace interference is obtained. “An” of theinterlace signal 244 is also divided by a color division section 242 andinput to a color synthesis section 243 without passing through thevertical filter 142. In the color synthesis section 243, the signal fromthe color division section 242 and the signal from the vertical filter142 are synthesized (½(A+B)). Then, the resultant signal is compressedby an MPEG encoder.

A vertical filter 143 performs a difference calculation, i.e., ½(An−Bn),thus obtaining a high frequency component, i.e., difference information.This signal is compressed by an MPEG encoder without being combined withthe color signal. Accordingly, the amount of the difference informationis advantageously reduced by the amount of the color signal.

FIG. 23 is a view representing the concept of the structure of FIG. 22.This system is referred to as multiple angle video data divisionmultiplex system (MADM) since a video signal is divided into vertical orhorizontal high frequency and low frequency components and recorded inthe state of being divided into pictures of multiple angles. As shown inFIG. 23, a signal is divided into a basic signal (sum signal) and a subsignal (difference signal) by a sum calculation section 141 and adifference calculation section 143. The resultant signals areMPEG-encoded and then recorded as an interleave block in units of 1 GOP.At this point, the amount of the information can be reduced by 20% byperforming 3-2 transform of the basic signal and the sub signal insynchronization with each other. It is efficient to use, as the basicsignal, “IBBPBBPBBPBBPBB” which is shown as a main GOP structure 244used for the ordinary MPEG encoding. In this structure, an I frame 246,B frames 248 and P frames 247 are alternately arranged. In the case ofthe difference signal, experiments have shown that it is efficient tohave a structure including only I frames 246 n and P frames 247 due tothe profile pattern, for example, “IPPPPPPPIPPPPPPP” shown in a sub GOPstructure 245. The efficiency is improved by changing the setting forthe sub GOP structure.

FIG. 23 shows an example in which a 525P video signal is divided intotwo in a vertical direction. FIG. 58 (described below) shows an examplein which a 525P video signal is divided into two in a horizontaldirection. In an alternative manner, a 60-frame 525P signal is dividedby frame division means into 30 odd frames and 30 even frames. In thiscase, the respective 30P signals are transformed into two 60-fieldinterlace signals, and each of the signals are MPEG-encoded to berecorded in the MADM system. Such encoding is performed in a progressivemanner, and therefore encoding efficiency is improved as in the case ofthe movie. Thus, the recordable time period of the same disk isextended.

When such a signal is reproduced by a non-MADM reproduction apparatus, a30P (one-channel) 525 interlace signal is reproduced. Such a signallacks necessary frames and is distorted.

When such a signal is reproduced by an MADM reproduction apparatus, a30P signal as a basic signal and a 30P signal as a sub signal arereproduced. These two 30-frame signals are synthesized into a 60-framenormal 525P signal by frame synthesis means including a frame buffer,and then output.

When a line doubler is added to an output section for the 525P signal, a1050P video signal is obtained.

When a 525 interlace signal is input to a sum signal section of thesynthesis section of the MADM reproduction apparatus and the value of 0is input to a difference signal section of the synthesis section, a 525Ppicture is obtained. Such a manner of input has the same effect as theline doubler. This method allows even an 525 interlace signal to beoutput as a 525P signal. Accordingly, all types of pictures can beviewed by simply connecting one cable to a progressive input terminal ofthe MADM reproduction apparatus.

In FIG. 23, ½(A+B) and ½(A−B) are used as expressions for calculationfor a two-tap filter. The separation frequency corresponds to about 300scanning lines.

When a four-tap filter as shown in part (c) of FIG. 46 is used, thenumber of scanning lines corresponding to the separation frequency canbe reduced to about 200. An example of using such a frequency will bedescribed. When the amount of information represented by the basicsignal is too large to encode the information, it is advantageous toreduce the number of scanning lines corresponding to the separationfrequency to less than 300, for example, 220. In this case, the amountof information represented by the basic signal is significantly reducedand thus the information can be encoded. Although the amount ofinformation represented by the sub signal, i.e., difference signal isincreased, it is not serious because the difference signal does notinclude color information and thus originally contains only a smallamount of information. Therefore, there is no problem of insufficiencyin the encoding capability of the encoder. An original picture isreproduced normally by the following setting. The filter information canbe contained in a filter identifier 144 in FIG. 50. The filtercharacteristics are changed in units of 1 cell or 1 GOP by altering theconstant of the sum calculation section and the difference calculationsection by filter separation frequency alteration means of thereproduction apparatus with reference to identifiers 100, 101 and 111.By such setting, a high rate picture, which is usually difficult toencode, can be encoded.

Returning to FIG. 22, the MPEG encoder section synthesizes an oddinterlace signal 79 a and an even interlace signal 80 a and alsosynthesizes an odd interlace signal 79 b and an even interlace signal 80b, thus obtaining frame signals 81 a and 81 b. The frame signals 81 aand 81 b are compressed by MPEG compression sections 82 a and 82 b togenerate compression signals 83 a and 83 b. Interleave blocks 84 a, 84 band 84 c each including 10 to 15 frames of the compression signals 83 aand 83 b corresponding to 1 GOP or more are generated. Compressionsignals obtained from an identical progressive signal are provided withan identical time stamp by time stamp provision means, and then thesignals are recorded on an optical disk 85.

The progressive signal recorded on the optical disk 85 is reproduced bya 2× reproduction apparatus shown in FIG. 21. The reproduced signal isdivided by a division section 87 into a stream of interleave blocks 84 aand 84 c and another stream of an interleave block 84 b. Then, thestreams are extended by extension sections 88 a and 88 b into framesignals 89 a and 89 b each having 720×480 pixels. The progressive signalis divided by field division sections 71 a and 71 b into odd fields 72 aand 72 b, and even fields 73 a and 73 b on a time axis, as by thereproduction apparatus shown in FIG. 20.

In FIG. 21, unlike the apparatus in FIG. 20, the odd fields 72 a and 72b of channel A 91 and channel B 92 are synthesized by a synthesissection 90 using a sum calculation circuit and a difference calculationcircuit. The even fields 73 a and 73 b are synthesized in the samemanner. Thus, channel A 91 and channel B 92 are synthesized in a zigzagmanner. As a result, progressive signals 93 a and 93 b are obtained andoutput from a progressive video output section 94.

In this manner, a progressive video signal, i.e., non-interlace NTSCsignals of 525 scanning lines is obtained by the reproduction apparatusaccording to the present invention. In this example, a progressivesignal of 480 scanning lines is obtained. The reproduction section 95performs 2× reproduction.

Advantageously, a movie or the like recorded in a conventional opticaldisk are also reproduced as a progressive picture.

FIG. 23 shows an example in which the signal is divided in a verticaldirection by the MADM system. With reference to FIG. 58, an example inwhich the signal is divided in a horizontal direction by the MADM systemwill be described. A wide 525P picture of, for example, 1440×480P hasbeen studied for movies. Such a signal is transformed into an interlacesignal of 1440×480i by a 3-2 transform section 174. The signal isdivided by a horizontal filter section 206 a into two in a horizontaldirection. FIG. 59 illustrates the principle of the filter in parts (a)and (b). As shown in part (b), 1440 dots are divided into odd dots 263 aand 263 b, and even dots 264 a and 264 b. Where the odd dots are labeledas “Xn” and the even dots are labeled as “Yn”, a sum signal is obtainedby X+Y and a difference signal is obtained by X-Y. As a result, two 525Por 525i signals, each of 720×480, are obtained as shown in part (b) ofFIG. 59.

Returning to FIG. 58, the number of horizontal dots of such a horizontalsum signal is reduced to 720. Since the signal is passed through thehorizontal filter, however, aliasing distortion is as low as that of anNTSC signal. A conventional reproduction apparatus reproduces only thesum signal and accordingly provides a DVD picture of the same quality.The difference signal represents only a profile formed of line-drawing.However, since the difference signal is restricted by a second videosignal output restriction provision section 179 so as not to bereproduced by an ordinary reproduction apparatus, no problem occurs. Thesum signal and the difference signal are respectively encoded into MPEGstreams by a first encoder 3 a and a second encoder 3 b, and subjectedto interleaving in units of an interleave block of 1 GOP or more andMADM-multiplexed.

As shown in FIG. 50, in the case of a movie, a signal is transformed bya 3-2 transform section 174 and MADM-recorded as an MPEG signal togetherwith 3-2 transform information 174 a.

In the case of the movie, 24 frames are reproduced in one second.Accordingly, a 1440×480P progressive picture is reproduced based on twointerlace signals by a 2× reproduction apparatus. The scope size of themovie is 2.35:1. The format of 1440×480P is suitable for the scope sizeof 2.35:1 in terms of the aspect ratio. Thus, a wide screen 525P iseffectively reproduced.

When a movie on the optical disk for a IX interlace reproductionapparatus is reproduced by the reproduction apparatus shown in FIG. 20,a 24-frames/sec. progressive signal is obtained in an MPEG recordersince a movie signal is a progressive signal having 24 frames/sec. Theprogressive signal is reproduced by detecting that the optical diskincludes a movie by detection means or by transforming the 24-frame/sec.signal into a 60-frame/sec. progressive signal by the 3-2 transformsection 174. An interlace picture with no interference is obtained byfiltering the progressive signal by a vertical filter with reference tothe filter identifier.

An optical disk 85 encoded with reference to FIG. 22 is reproduced bythe reproduction apparatus 65 conforming to the progressive system.Then, a channel-A interlace signal 74 a is reproduced. A conventionalinterlace DVD player has only channel A but not channel B. Therefore,when the optical disk 85 according to the present invention is mountedon the conventional interlace DVD player, the channel-A interlace signalis obtained. As can be appreciated, an optical disk according to thepresent invention provides a progressive signal when reproduced by areproduction apparatus according to the present invention, and providesan interlace signal of the same contents when reproduced by aconventional reproduction apparatus. Thus, the optical disk according tothe present invention realizes complete compatibility even with theconventional reproduction apparatus.

In the MPEG encoder shown in FIG. 22, an interlace interference removalcompression filter 141 is provided to significantly reduce the aliasingdistortion.

Hereinafter, encoding of a 3D picture will be described in detail.

A right-eye signal 97 and a left-eye signal 98 are input into arecording apparatus 99 in the same manner as the sum signal and thedifference signal of the progressive signal described with reference toFIG. 22. Since this is an interlace signal, odd field signals 72 a and72 b and even field signals 73 a and 73 b are input every 1/60 second.The signals 72 a and 73 a and the signals 72 b and 73 b are synthesizedby synthesis sections 101 a and 101 b into 1/30 sec. frame signals 83 aand 83 b. These signals are compressed by compression sections 103 a and103 b into compression signals 83 a and 83 b. Interleave blocks 84 a, 84b and 84 c, each including frames of these signals corresponding to 1GOP or more, are generated. The interleave blocks 84 a, 84 b and 84 care alternately located and recorded on the optical disk 1. When data inthe resultant optical disk is mounted on the reproduction apparatusshown in FIG. 24 for reproduction, the 3D/PG picture arrangementinformation reproduction section 26 described above with reference toFIG. 5 detects a PG identifier in the disk. Therefore, the reproductionapparatus (104) is put into a 3D reproduction mode as shown in FIG. 24.The 3D picture in the optical disk is divided by a division section 68into channel A and channel B. The data in the channels are extendedrespectively by extension sections 88 a and 88 b and then divided intofield signals by field division sections 71 a and 71 b. The operation ofthe reproduction apparatus up to this point is the same as in the caseof FIG. 21.

A feature of the reproduction apparatus shown in FIG. 24 is that thefield division section 71 a outputs odd field signals and even fieldsignals while switching the output order thereof by an output transformsection. When the signals are sent to a progressive TV, i.e., a TVhaving a field frequency of 120 Hz, the signals are output from aprogressive output section 105 in the order of a channel-A odd fieldsignal 72 a, channel-B odd field signal 72 b, channel-A even fieldsignal 73 a, and channel-B even field signal 73 b. Thus, the right-eyesignals and the left-eye signals are output alternately and in the orderof the odd field and then the even field. Accordingly, a flickerlesspicture having matching right-eye and left-eye information is obtainedthrough switch-type 3D spectacles.

When the signals are sent to an ordinary TV, the channel-A odd fieldsignal 72 a and the channel-B even field signal 73 b are output from anNTSC output section 106. Then, a 3D picture displaying natural motionsis obtained through 3D spectacles although the picture includes flicker.

By combining the progressive system and the 3D picture reproductionsystem according to the present invention, a high definition 3D pictureincluding a right-eye picture and a left-eye picture is realized. Thiswill be described with reference to FIG. 25. A reproduction apparatus107 performs 4× reproduction. When reproducing a DVD, 80% of such atransfer rate is sufficient. In the embodiment where interleave blocks108 a, 108 b, 108 c and 108 d of right progressive signals A and B andleft progressive signals C and D are arranged with no interval as shownin FIG. 25, the optical pickup does not need to jump for continuousreproduction. In the case of a DVD, only 80% of the information isreproduced. The reproduction rate can be 3.2× in lieu of 4× in the caseof continuous reproduction. Such a continuous arrangement advantageouslyreduces the reproduction rate.

The signal is divided into interleave blocks 108 a, 108 b, 108 c and 108d, and signals for channels A, B, C and D are reproduced. The videosignals extended by extension sections 69 a, 69 b, 69 c and 69 d aresynthesized by synthesis sections 90 a and 90 b as in FIG. 21, and twoprogressive signals are output from progressive output sections 110 aand 110 b. The two progressive signals are respectively a right-eyesignal and a left-eye signal. Accordingly, a progressive 3D picture isobtained by the reproduction apparatus 107. When a 4×MPEG chip is used,only one chip is sufficient and avoids an increase in the number ofcomponents. The 4×MPEG chip realizes recording and reproduction ofpictures of four different contents. In this case, pictures aredisplayed on a 4-part multi-screen TV simultaneously with one opticaldisk.

A feature of the present invention is to provide compatibility among allthe apparatuses and media. When data on a disk 106 in FIG. 25 isreproduced by a conventional reproduction apparatus, an interlace signalfor either the right eye or the left eye is output The picture is notdeteriorated although the reproduction time is reduced to ¼. However, atwo layer DVD stores data for 2 hours and 15 minutes. Almost all moviesare accommodated in such a DVD.

When data on the disk 106 in FIG. 25 is reproduced by a 2×3D/progressivereproduction apparatus according to the present invention, the userswitches from a 3D interlace picture to a one-channel progressivepicture or vice versa by sending an instruction to a control section 21through a channel selection section 20 from an input section 19 (seeFIG. 9). As described above, the present invention has an effect ofproviding complete compatibility analogous to that between the monauralrecords and stereo records discussed in the past.

According to the 2× and 4× reproduction apparatuses according to thepresent invention, pictures of various qualities are obtained in variousdisplay manners.

As described above, according to the present invention, when a 3Didentifier is not available, the pointer is read and the optical headjumps. When a 3D identifier is available, the reproduction process ischanged so that the pointer of one of the immediately previousinterleave blocks is read and accessed. Thus, a 3D picture is recordedwithout changing the format.

A method for performing recording and reproduction while a scope-sizemovie screen is divided into two.

In FIG. 20, an optical disk 1 having two-screen interlace signals isreproduced. Now, with reference to FIG. 40, this concept is applied to ascope-size (2.35:1) super wide screen 154. The super wide screen 154 isdivided into three, i.e., a center screen 156 and side screens 157 and158 by a screen division section 155. The position of division isrepresented by a center shift amount 159. The center picture 156 d iscompressed as a first video signal. The side pictures 157 and 158 arecompressed together as a second video signal. The compression signalsare processed with interleaving and are recorded on an optical disk 191together with the center shift amount 159. In this case, the secondvideo signal, which represents a picture obtained by sewing together twodifferent quality pictures, is not desired to be output. Accordingly, asecond video signal restriction information provision section 179 addsreproduction restriction information such as, for example, passwordprotection to the second video signal stream. Then, the reproductionapparatus cannot reproduce the second video signal independently. Inthis manner, it is prevented that the user views an abnormal picture ofonly the second video signal. In this case, a progressive reproductionapparatus reproduces both the first and second video signals to realizea wide screen.

When such an optical disk is reproduced by the reproduction apparatus inFIG. 20, the second video signal is not independently output. From theoptical disk, the center shift amount 159 is reproduced by a centershift amount reproduction section 159 b. A wide picture synthesissection 173 uses the center shift amount 159 to synthesize a scope-sizepicture. The 3-2 transform section 174 performs 3-2 pull-down transformshown in FIG. 41 to transform a 24-frame/sec. signal of the movie into a60-fields/sec. interlace signal or a 60-frames/sec. progressive signal.As shown in FIG. 41, both the extension and wide picture synthesis areperformed. The 3-2 transform performed by the 3-2 transform section 174is as follows. A synthesis picture 179 a having 24 frames/sec. istransformed into three interlace pictures 180 a, 180 b and 180 c. Asynthesis picture 179 b is transformed into two interlace pictures 180 dand 180 e. Thus, the picture having 24 frames/sec. is transformed into a60-fields/sec. interlace picture. A progressive picture 181 can beoutput as three progressive pictures 181 a, 181 b and 181 a and twoprogressive pictures 181 d and 181 e.

An other method for dividing a screen is as follows. As shown in FIG.40, a 1440×480 screen 154 is divided into two horizontal separationscreens 190 a and 190 b each having 720×480 pixels. Such division isperformed by separating odd number of columns of pixels from even numbercolumns of pixels by a picture horizontal division section 207. Thesescreens 190 a and 190 b are compressed as a first video signal and asecond video signal in a similar manner to the above-described mannerand recorded on the optical disk 191. In order to avoid aliasingdistortion, two pixels are added by a horizontal filter 206 shown inFIG. 46 at a specific addition ratio, so that the high frequencycomponent in the horizontal direction is attenuated. Such processingavoids generation of moiré, which appears when the optical disk isreproduced by an existing reproduction apparatus at 720 dots.

When the optical disk 191 is reproduced by the reproduction apparatus 65shown in FIG. 20, the horizontal separation screens 190 a and 190 b aredecoded. When the decoded signals are synthesized by the wide picturesynthesis section 173, an original 1440×480-pixel screen 154 a isobtained. In the case of movies, 3-2 transform is performed bysynthesizing the screen 154 a as shown in FIG. 41.

The second method of horizontally dividing the screen is advantageous inproviding a level of high compatibility for the following reason. Thefirst video signal and the second video signal both represent anordinary 720×480-pixel picture obtained by dividing the original1440×480-pixel picture into two by a horizontal line. Accordingly, evenwhen the second video signal is erroneously reproduced by an ordinaryreproduction apparatus such as a DVD player, the resultant picture hasthe same aspect ratio as that of the original picture. Such a divisionsystem advantageously realizes reproduction of an interlace picture byan ordinary reproduction apparatus, reproduction of a 525 progressivepicture by a progressive reproduction apparatus, and reproduction of awide screen picture having a scope of, for example, 720P by a 720P highresolution reproduction apparatus. Such advantages are conspicuous inthe case of movies, which can be reproduced at the rate of 2×.

This method is applied as shown in FIG. 44. A 1440×960 progressivepicture 182 a is divided in horizontal and vertical directions by ahorizontal and vertical division section 194 of a picture divisionsection 115 using, for example, sub-band filter or wavelet transform.Then, a 525 progressive picture 183 is obtained. This is divided intointerlace signals 184 and recorded as a stream 188 a.

Interpolation information 185 is divided into four streams 188 c, 188 d,188 e and 188 f in a similar manner and recorded in units of aninterleave block. The maximum transfer rate of each interleave block is8 Mbps by the DVD format. When the interpolation information 185 isdivided into four streams, the transfer rate of 32 Mbps is obtained. Inthe case of six angles, the transfer rate of 48 Mbps is obtained. Thus,720P and 1050P HDTV pictures can be recorded. In a conventionalreproduction apparatus, a stream 188 a is reproduced and an interlacepicture 184 is output. Regarding the streams 188 c, 188 d, 188 e and 188f, output restriction information is recorded on an optical disk 187 bya picture processing restriction information generation section 179.Therefore, an ugly picture of interpolation information 185 such asdifferential information or the like is not output in error. An opticaldisk compatible with HDTV and NTSC is realized by dividing a signal in ahorizontal direction by the system shown in FIG. 44.

In FIG. 20, an interlace signal is obtained by the transform performedby the interlace transform section 175, and as a result, a scope-sizescreen 178 is obtained. A 525P progressive signal is also output on ascope-size screen in a similar manner. When viewed by a 720P monitor, a525P signal is transformed into a 720P progressive signal by a 525P/720Ptransform section 176, as a result of which a letter box-type 720Pscreen 177 having 1280×720 or 1440×720 pixels (picture has 1280×480 or1440×480 pixels) is output. A scope-size picture (2.35:1) has 1128×480pixels. A picture having a similar aspect ratio to this is obtained. Amovie signal has 24 frames/sec. Therefore, the transfer rate of theprogressive picture is 4 Mbps. When the scope-size picture is recordedby the 2-screen system according to the present invention, the transferrate is 8 Mbps. Since a two-layer DVD can store data for about 2-hoursand 15 minutes, a 720P or 525P high definition progressive picture canbe recorded on one optical disk. Such data is output on a conventionalTV as an interlace signal, needless to say. As described above, thescope-size (2.33:1) picture of the movie can be output as a 525P or 720Ppicture.

Hereinafter, a specific method for recording and reproducing a 1050interlace signal will be described. An even field 208 a of a 1050interlace signal is divided into two pictures 208 b and 208 c byhorizontal division means 209. Two pictures 208 b and 208 c arerespectively divided by vertical division means 210 a and 210 b toobtain pictures 208 d and 208 e, and 208 f and 208 g. An odd field 211 ais divided in a similar manner to obtain pictures 211 d, 211 e, 211 fand 211 g. In this case, the pictures 208 d and 211 d act as mainsignals and an interlace picture is output by an existing reproductionapparatus. Horizontal filters 206 b and 206 c and vertical filters 212 aand 212 b, inserted for preventing interlace interference and the like,reduce aliasing distortion of the reproduced picture.

With reference to FIGS. 27, 28, 42 and 49, the file structure andidentifiers for pictures will be described. FIG. 27 shows a logicalformat of DVD. Each logical block includes a video file. As shown inFIG. 28, a minimum unit of a system stream is referred to as a “cell”.In a cell, picture data, audio data and sub picture are recorded in apacket in units of 1 GOP.

A cell 216 (see FIG. 18) of a main signal of a first stream has a packet217. A provider defined stream in the packet 217 has a capacity of 2048bytes. The provider defined stream includes a progressive identifier 218indicating whether the signal is progressive or interlace, a resolutionidentifier 219 indicating whether the resolution is 525, 720 or 1050, adifferential identifier 220 indicating whether or not the interpolationsignal is a differential signal from the main signal, a filteridentifier (described later), and sub stream number information 221indicating the stream number of a first sub stream.

With reference to FIG. 52, a process for performing reproduction using apicture identifier 222 will be described.

From the optical disk, reproduction process control information 225 isfirst read from management information 224. Since the information 225includes restriction information on VOB, a 0th VOB 226 a is onlyconnected to a first VOB 226 b having a main picture in an existingreproduction apparatus. Since the 0th VOB 226 a is not connected to asecond VOB 226 c having an interpolation signal such as differentialinformation, an ugly picture such as differential information is notoutput by the existing reproduction apparatus. Each VOB of the mainsignal has a picture identifier. Since the progressive identifier=1 andresolution identifier=00 (525) in the first VOB 226 b and the second VOB226 c, a progressive signal having 525 scanning lines is reproduced froma progressive or high definition HD reproduction apparatus.

In a picture identifier 222 of the next VOB 226 d, the progressiveidentifier=0 and the resolution identifier 219=10. An interlace signalhaving 1050 scanning lines is output. VOBs 226 e, 226 f and 226 g areinterpolation information. Thus, an NTSC signal is output by aconventional reproduction apparatus, an interlace signal having 720horizontal pixels and 1050 vertical pixels is output by a progressivereproduction apparatus, and a full HDTV-format signal having 1050scanning lines is output by a high definition reproduction apparatus.The picture identifier 222 can be recorded in the management information224.

With reference to FIG. 53, the relationship among VPTS (videopresentation time stamp) of the sub track of interleave blocks, i.e.,decoding output time, will be described. In the first VOB 226 b as themain signal, interleave blocks 227 a, 227 b and 227 c are recordedtogether with VPTS1, VPTS2 and VPTS3. In the second VOB 226 c,interleave blocks 227 d, 227 e and 227 f are recorded together withVPTS1, VPTS2 and VPTS3. A conventional player reproduces the interleaveblocks 227 a, 227 b and 227 c at 1×. Since the main signal includes anaudio signal, the audio signal is also reproduced. A progressive playerfirst reproduces the interleave block 227 d of the second VOB 226 a as asub signal and stores the block in a buffer memory. After the storage,the progressive player reproduces the interleave block 227 a of thefirst VOB 226 b. The audio and video signals are synchronized with thesynchronization information of the interleave block 227 a. Since theaudio signal is included in the main signal, the main signal and the subsignal shown in parts (2) and (3) of FIG. 53 are output insynchronization with the audio signal. In this case, a track jump isperformed between the interleave blocks 227 a and 227 e.

Thus, a progressive signal shown in part (4) of FIG. 53 is output. Bychecking the VPTS of the interleave blocks by the reproductionapparatus, the main signal and the sub signal are decoded insynchronization and synthesized, thereby obtaining a normal progressivesignal.

FIG. 54 shows an arrangement of signals in a simultaneous cast system bywhich an NTSC signal and an HDTV signal are recorded as interleaveblocks independently at the same time. In the VOB 227 a as the mainsignal, a video signal and an audio signal 232 are recorded. In the VOBs227 b and 227 c, an HDTV compression video signal corresponding to about16 Mbps is recorded, 8 Mbps for each, by the interleave system. Aconventional player and a progressive player shown in parts (1) and (2)of FIG. 54 reproduces an NTSC (525i) signal. An HDTV player shown inpart (3) of FIG. 54 reproduces a 16 Mbps HDTV signal as a result ofobtaining only audio data from the first VOB 227 a, reproducing a firstsub picture and a second sub picture from the VOBs 227 b and 227 c, andsynthesizing these data. Since the reproduction of the sub signals isrestricted by the reproduction process control information 225, anexisting DVD player does not reproduce an HDTV compression signal evenwhen the user erroneously operates the player. Thus, an NTSC signal isoutput by the existing player, and an HDTV signal is output by the HDTVplayer. FIG. 55 is a block diagram of a reproduction apparatus. Theoperation of the reproduction apparatus is not described in detail sinceit is similar to the operations described above. A reproduction signalfrom the optical disk is divided by an interleave block division section233. A main signal is decoded by an audio decoder 230 of an NTSC decoder229, and a first sub signal and a second sub signal which are each an 8Mbps stream, are decoded by an HDTV decoder 231. Thus, an HDTV signaland an audio signal are output. The data in the optical disk isreproduced as an NTSC signal even by a conventional reproductionapparatus by simultaneous casting. Moreover, according to the presentinvention, a transfer rate of 16 Mbps is obtained when two interleavestreams are used. Accordingly, a standard HDTV MPEG-compression signalis recorded as it is. With a DVD, a transfer of only 16 Mbps is obtainedwith two interleave blocks. Since an HDTV compression video signal is a16 Mbps signal, audio data cannot be recorded. According to the presentinvention, audio data of the NTSC signal of the main signal is used.Therefore, an audio signal can be recorded even when an HDTV signal isrecorded with two interleave blocks.

Now, a method for removing interlace interference will be described.When a progressive signal is transformed into an interlace signal byremoving unnecessary components, aliasing distortion is generated andthus a moiré of a low frequency component is generated. A 30 Hz lineflicker is also generated. In order to avoid these inconveniences, thesignal needs to be passed through interlace interference removal means.Interlace interference removal means 140 is added to a progressivesignal section of a progressive/interlace transform section 139 of therecording apparatus in FIG. 22 (described above). When a progressivesignal is input, the interlace interference removal means 140 a detectsa video signal having a high probability of being interfered with fromthe input progressive signal, and passes only such a video signalthrough an interlace interference removal filter 141. For example, inthe case of a picture having a low vertical frequency component,interlace interference does not occur. In such a case, the filter isbypassed by a filter bypass route 143. Such an operation alleviates thedeterioration in the vertical resolution of the picture. The interlaceinterference removal filter 141 includes a vertical filter 142.

In part (a) of FIG. 46 (time and space frequency diagram), the hatchedarea represents an aliasing distortion generation area 213.

The aliasing distortion generation area 213 can be removed by a verticalfilter. Specifically, as shown in part (c) of FIG. 46, three linememories 195 are provided. Regarding a progressive signal having 480lines, picture information on the target line (n'th line) and pictureinformation on the immediately previous and subsequent lines ((n−1)thline and (n+1)th line) are added together by an adder 196. Thus,information of one line is obtained, and 240 interlace signals aregenerated. Such processing filters the information in a verticaldirection, resulting in alleviation in the interlace interference. Bychanging the adding ratio of the three lines, filter characteristics canbe changed. This is referred to as a “vertical three-line tap filter”.By changing the adding ratio of the center line with respect to theimmediately previous and subsequent lines, a simpler vertical filter canbe obtained. As shown in part (d) of FIG. 46, line information can beprocessed with a vertical filter after, for example, the (n−1)th line ofthe previous frame and the (n+1)th line of the subsequent frame (evenlines) are developed on an identical space, in lieu of a simple verticalfilter. Such a time vertical filter 214 has an effect of alleviatinginterlace interference, which occurs when a progressive signal on theoptical disk is reproduced by a non-progressive player and only aninterlace signal is listened. A horizontal filter 206 a is realized byadding two pixels in a horizontal direction to synthesize one pixel.Needless to say, however, such a filter deteriorates the resolution ofthe progressive picture. The filter effect is alleviated by preventingfiltering on a picture having a low probability of being interfered withor by changing the adding ratio to realize a vertical filter. When thefilter effect is weakened, the deterioration in the resolution of theprogressive picture is alleviated. A progressive reproduction apparatusaccording to the present invention filters the information sufficientlyto remove interlace interference during reproduction, so that it is notnecessary to filter the information when being recorded. When suchprogressive reproduction apparatuses replace the existing reproductionapparatuses in the future, filtering during recording will not benecessary. In such a case, there will be both filtered optical disks andunfiltered optical disks. The interlace interference removal means 140outputs an interlace interference removal identifier 144 to checkwhether or not the picture has been filtered and records the informationon the optical disk 85 by recording means 9.

With reference to FIG. 50, a specific method for recording a filteridentifier will be described. A filter identifier 144 is put in a headerin 1 GOP, which is an MPEG recording unit in one stream. “00” indicatesthat the signal is not filtered. “10” indicates that the signal has beenpassed through a vertical filter. “01” indicates that the signal hasbeen passed through a horizontal filter. “11” indicates that the signalhas been passed through a vertical and a horizontal filter. Since thefilter identifier 144 is put in the minimum unit of 1 GOP, the filtercan be turned on or off in units of 1 GOP in the reproduction apparatus.Accordingly, deterioration of the picture quality by double filtering isavoided.

With reference to parts (a) and (b) of FIG. 32, an operation of areproduction apparatus 86 a for reproducing an optical disk 85 will bedescribed. As in FIG. 21, two interlace pictures 84 a and 84 b arereproduced to synthesize a progressive picture 93 a. Notably, when theinterlace interference removal filtering identifier 144 is “ON” or whenspecial reproduction such as “slow” or “still picture” is not performedand a progressive picture is not output either, an interlace signal isoutput directly by an interlace output section at 1×. This is energyefficient.

When special reproduction is performed or when the interlaceinterference removal filtering identifier 144 is off, a “2×” instruction146 is sent from a control section 147 to a motor rotation speedalteration section 35. Then, the optical disk 85 rotates at 2×, and aprogressive picture is reproduced.

A method for removing interlace interference when the progressivepicture reproduced in this manner is output to an interlace TV 148 as aninterlace signal will be described. When the interlace interferenceremoval filtering identifier 144 is off, a determination switch circuit149 is switched to pass the progressive signal through the interlaceinterference removal filtering identifier 144. Then, two frames 93 a and93 b are transformed by an interlace transform section 139 into odd andeven interlace signals 72 a and 73 a. Thus, an ordinary interlace signalis output. In this case, a picture with no interlace interference isdisplayed on the interlace TV 148. Since the interlace interferenceremoval filter does not influence the interlace signal significantly,the interlace signal is not deteriorated. A progressive signal with nointerlace interference removal filter is output to a progressive signaloutput section 215. By the system of turning on and off the interlaceinterference removal filter by the reproduction apparatus, a progressivepicture with no quality deterioration and an interlace picture with noquality deterioration such as interlace interference are both obtained.

When slow reproduction of a speed of ½ or less and still picturereproduction is performed, the removing filter is weakened since theinterlace interference is alleviated.

Next, a method for improving special reproduction will be described.When an instruction to perform a slow or still picture reproduction isissued from the control section 147 through an operation input section150 to slow/still picture reproduction means 151, the interlacetransform section 149 divides the 480 lines of the frame 93 a into twofields using a frame processing section 152 to create and output an oddinterlace signal 72 b and an even interlace signal 73 b. Then, a low orstill interlace picture having a resolution of 480 with no blurring isdisplayed on the interlace TV 148. In a conventional interlacereproduction apparatus, the resolution needs to be lowered to 240 inorder to obtain a slow or still picture with no blurring. According tothe present invention, a slow or still picture having a resolution of480 with no blurring is obtained by transforming the interlace signalinto a progressive signal once and then transforming the progressivesignal back to the interlace signal. FIG. 32 illustrates this process inthe flowchart in part (a) (steps 153 a through 153 g). The detaileddescription of the flowchart is omitted.

With reference to FIG. 26, a method for outputting streams in twochannels continuously will be described. The two-channel streams arerecorded on an optical disk as pictures in cameras 1 and 2 by aninterleave system. A first stream from the disk is reproduced and thenswitched to a second stream.

With reference to FIG. 35, a method for switching a specific stream toanother stream smoothly with no disconnection when the contents of theoptical disk include a plurality of streams, i.e., when a plurality ofstreams are multiplexed will be described. As shown in part (1) of FIG.35, an optical disk 106 includes two different streams as a first stream111 of a first video signal and a second stream 112 of a second videosignal. The two streams are basically recorded substantially at the sameradius.

Usually, only the first video signal as a basic stream is reproduced.Accordingly, a first stream 111 a is reproduced and then a first stream111 b is continuously reproduced. When the user issues an instruction toswitch the first video signal to the second video signal from aninstruction input section 19 in FIG. 5 at time t=tc, a tracking controlcircuit 22 in FIG. 5 is used to access a track at a different radialposition, thereby outputting a second stream 112 b of the second videosignal at time t=tc.

Thus, as shown in part (2) of FIG. 35, the first video signal isswitched to the second video signal seamlessly with no disconnection attime t=tc in terms of the video, audio and sub picture signals.

A method for realizing such a seamless reproduction by synchronizing thevideo, audio and sub picture signals will be described later.

With reference to a timing diagram of parts (3) and (4) of FIG. 35, aspecific method for reproducing data will be described. As describedwith reference to the block diagram of FIG. 22, a progressive picture asthe first video signal is divided into main interlace video signals A1through An (Odd First) and sub interlace video signals B1 through Bn(Even First). The signals are recorded separately in first-angle andsecond-angle sub channels. Although not described with reference to FIG.22, a progressive picture as the second video signal is also dividedinto main interlace video signals C1 through Cn and sub interlace videosignals D1 through Dn. The signals are recorded separately inthird-angle and fourth-angle sub channels as shown in part (3) of FIG.35. Part (3) of FIG. 35 is a timing diagram of the principle shown inFIG. 36. The operation is the same.

FIG. 36 puts a focus on an interleave section of the recording apparatusshown in FIG. 22. A progressive signal as the first video signal isdivided by a first video signal division section 78 a into a main signal(Odd First) and a sub signal (Even First). The amount of information canbe reduced by finding a differential signal between the main signal andthe sub signal by a differential section 116 a and compressing the mainsignal and the sub signal to be recorded on the disk. In the case of aprogressive signal, the correlation between adjacent odd and even linesis quite strong, and accordingly the amount of information of adifferential signal between the two lines is small. Thus, the amount ofinformation to be recorded can be significantly reduced by finding thedifferential signal.

According to the present invention, the signals are recorded in adivided manner using the differential device 116 a as shown in FIG. 44.A 720P signal, i.e., a progressive picture having 720 lines or a 1050Psignal is divided by the picture division section 115 into 525 basicinformation 187, progressive picture 183 (or 525 interlace picture 184)and interpolation information 186. Differential information 185 betweenthe basic information 187 and the interpolation information 186 isobtained by the differential device 116 a. The differential information185 is divided by a second video signal division section 78 c and athird video signal division section 78 d into four streams 188 a, 188 d,188 e and 188 f. These streams are sent to a compression section 103 andprocessed with interleaving by an interleave section 113 a. Thus, sixstreams are recorded in the angles on an optical disk 187.

At this point, the streams 188 c, 188 d, 188 e and 188 f aredifferential information or interpolation information, and thus do notprovide a normal picture when being decoded by the reproductionapparatus and output onto a TV screen. Such an abnormal picture makesthe viewer feel uncomfortable. In order that the streams 188 c, 188 d,188 e and 188 f, including the interpolation information 186, recordedin different angles not be output by a non-progressive reproductionapparatus, restriction information is generated by the picture outputrestriction information generation section 179 and recorded on theoptical disk 187. Specifically, such information prevents a specificstream from being opened without a password. Processing the streams 188c, 188 d, 188 e and 188 f with such password protection prevents aconventional reproduction apparatus from opening these streams andavoids the situation where the user views the abnormal picture obtainedby decoding the interpolation information.

Returning to FIG. 36, the first video signal is thus compressed, so thatthe main signal of the first video signal is divided into A1 and A2interleave blocks 83 b and 83 d, each including 1 GOP or more. The mainsignal of the second video signal is divided into C1 and C2 interleaveblocks 83 a. The sub signal of the second video signal is divided intoB1 and B2 interleave blocks 83 e and 83 g and D1 and D2 interleaveblocks 83 f and 83 h. As shown in FIG. 36, a recording stream 117 isgenerated from these four pieces of data. In the recording stream 117,the blocks are arranged in the order of A1, B1, C1, D1, A2, B2, C2, andD2. The recording stream 117 is recorded on an optical disk 115 byrecording means 145. A1, B1, A2 and B2 correspond to the first videosignal of the progressive signal. Accordingly, the signals are recordedon the optical disk 115 in the order of the first video signal, thesecond video signal, the first video signal and the second video signal.A seamless reproduction performed by the AV synchronization section willbe described later.

In the above description, 1 GOP or more of the MPEG signal is recordedin each interleave block. Precisely, one interleave block is restrictedto about 0.5 seconds or less. Therefore, only 30 fields of a videosignal can be recorded at the maximum. Accordingly, only 30 GOPs can berecorded in one interleave block at the maximum. One interleave block ofthe present invention is limited to 1 GOP or more and 30 GOP or less.

A method for compression will be described. Interlace signals 79 a and80 a of a first VOB 118 are put together as a field pair 125 a andencoded by a frame encoding section 123 a into a frame encoded signal127 a.

A dummy field 121 of a second VOB 119 is first encoded by a fieldencoding section 124 b in a compression section 82 b on a field-by-fieldbasis into a field encoded signal 129. Next, an even interlace signalBob and an odd interlace signal 79 b, which are sub signals, are puttogether as a first field pair 126 a, frame-encoded by a frame encodingsection 123 b in the compression section 82 b into a frame encodedsignal 128 a.

Thus, an Odd First dummy field is added to the second VOB 119. Thus, thesecond VOB signal 119 starts with an odd interlace signal. Since thesignals are recorded in the order of an odd interlace signal and then aneven interlace signal, the signals are reproduced smoothly by a DVDplayer. In this case, one progressive signal corresponds to frameencoded signals 127 a and 128 a. Due to the field encoded signal 129obtained from the dummy field, there is an offset time period 130 of tdbetween the frame encoded signal 127 a from the main signal and theframe-encoded signal 128 a from the sub signal. Accordingly, it isrequired to output the sub signal earlier by the offset time period whenreproducing the progressive signal.

With reference to FIG. 34, the operation of the reproduction apparatus86 described referring to FIG. 21 will be described in more detail. Asignal from the reproduction section 95 is divided into a first VOB 118as the main signal and a second VOB 119 as the sub signal. The first VOB118 originally starts with an odd line and thus can be extended as itis. The second VOB 118 has a dummy field 129 at the start thereof forauthoring. Reproduction of the second VOB 118 as it is results ingenerating an offset time period 119 of td between the main signal andthe sub signal. Since it is time-consuming to synthesize the firstprogressive signal in such a case, a picture corresponding one VOB and apicture corresponding the next VOB are not continuous. In order to avoidthis, the present invention provides two method for skipping a dummyfield 121.

According to a first method, a field encoded signal 129 at the start ofthe second VOB 119 is once input to an extension section 132. Whenprogressive identification information is detected during or after fieldextension, a progressive processing switching section 135 is switched toYes. Thus, the dummy field 121 is skipped by dummy field bypassing means132 so that an even interlace signal 80 b is first output and then anodd interlace signal 79 b is output. This signal is synchronized bysynchronization means 133 with an audio signal 134 and a sub picturesignal 135 such as subtitles which are recorded in the main signal. As aresult, progressive pictures 93 a and 93 b are output through aprogressive transform section 90. In the embodiment where the dummyfield 121 is bypassed in this manner, an odd field and an even field areoutput in synchronization with each other. Thus, a progressive signal,an audio signal and a sub picture signal with matching time axes areoutput. When progressive identification information is absent, theprogressive switching section 135 is switched to No, and thus the dummyfield 121 is not bypassed. Progressive transform is not performed. Thus,an interlace signal 136 is output. Such an output of the interlacesignal 136 occurs in a conventional DVD player without a progressivefunction. As described above, the dummy field bypassing means 132 isturned on for processing a progressive signal. Otherwise, the dummyfield bypassing means 132 is turned off, so that an ordinary fieldencoded interlace signal is normally output without dropping the field.

A second method is used when the dummy field 129 is field-encoded into 1GOP frames and can be separated from the frames of the sub signal.Before decoding, the field encoded signal 129 obtained by encoding thedummy field is skipped by 1 GOP by dummy field encoded informationbypassing means 137. The skipped information is input to a buffer 131 b,or skipping is performed when data is output from the buffer. To theextension section 88 b, only the frames of the sub signal paired withthe main signal or field information is input. Thus, by ordinary meansdescribed above referring to FIG. 21, the even interlace signal 80 andthe odd interlace signal 79 b are extended, interlace-transformed,synchronized with the main signal, and transformed into progressivesignals 93 a and 93 b by the progressive transform section 90.

According to the second method, the dummy field is removed while thedummy field is in the form of the encoded information. Therefore, thedummy field is not required to be processed by the buffer section 131 bor the extension section 88. This method is appropriate for putting afield encoded in units of 1 GOP to the start of the second VOB.

According to the first method, the dummy field 129 and the field signalsin each frame 127 a are field-encoded together to generate a unit of 1GOP. This is efficient where a dummy field is inserted at the start ofone interleave block in, for example, a seamless multiple angle systemhaving a high recording efficiency. The first method has an effect ofextending the recording time period.

By skipping the dummy field 121 only for progressive processing in thismanner, progressive pictures can be reproduced with no disconnection atthe border between adjacent VOBs or between interleave blocks in thecase of a seamless multiple angle system.

Such processing will be described with reference to the flowchart inFIG. 37. In step 138 a, an instruction to start reproduction of (2n−1)thangle data is issued. In step 138 b, whether or not a progressiveidentifier is present is checked. If yes, the processing jumps to step138 f. If no, in step 138 c, whether or not the following threeconditions are fulfilled is checked. Condition 1 is that there is onefield (or an odd number of pieces of fields) of GOP at the start of then'th angle VOB. Condition 2 is that one field of GOP is not existentcontinuous to one field of GOP. Condition 3 is that the leading GOP ofthe (2n−1)th angle does not correspond to one field. Then, in step 138d, whether or not the three conditions are fulfilled is checked. If no,in step 138 e, interlace processing is performed to output only the(2n−1)th angle. If yes, in step 138 f, the processing is switched toprogressive processing. In step 138 g, whether or not the reproductionis to be performed from the start of the (2n−1)th angle VOB is checked.If no, the processing jumps to step 138J. If yes, in step 138 h, then'th angle VOB is output while dropping the picture of the first onefield or GOP corresponding to one field. When the (2n−1)th angleincludes an audio signal, the VOB is output while skipping the firstoffset time period dt (default value: 1/60 sec.). In step 138 j, themain signal of the (2n−1)th angle and the sub signal of the 2n'th angleare decoded, synchronized and synthesized into a progressive signal. Instep 138 k, a progressive picture is output. When a seamless multipleangle output is performed in step 138 m, the processing advances to step138 n, where each interleave block of the (2n−1)th angle (i.e., subsignal) is field-decoded, and the output is performed while the firstblock is skipped. Alternatively, the outputting order of the odd linesand the even lines is inverted at the time of interlace transform. Instep 138 p, the progressive picture is synthesized and output.

Due to authoring, several seconds of dummy field is inserted at thestart of the multiple angle VOB. The dummy field group at the start ofthe VOB is read. In a similar manner, the leading address at which themultiple angle VOB starts is read from the PGC data. For ordinaryreproduction, data is read from the start of the VOB. For only 3D orprogressive reproduction, the dummy field is skipped and the data isread from the starting address of the VOB corresponding to each of themultiple angle VOB. Thus, 3D or progressive pictures are prevented frombeing interrupted at the border of adjacent VOBs.

So far, the MADM system has been described. Hereinafter, a providerdefined stream picture division multiplex system (PSDM) as anothersystem will be described. FIG. 61 is a block diagram of the PSDM systemof a vertical division system. FIG. 62 is a block diagram of the PSDMsystem of a horizontal division system. FIG. 63 shows a signal format ofthe PSDM system.

As shown in FIG. 63, a DVD video signal has 10.08 Mbps, and a providerdefined stream is defined separately from a basic stream. A sum signaldescribed with reference to FIG. 23 can be added to the basic stream andput into the provider defined stream. Such a signal can be reproduced bychanging the circuit even with a normal 1× drive. According to theexperiments performed by the present inventors, a satisfactoryprogressive picture is obtained when the sum signal is 6 Mbps and thedifference signal is 3 Mbps. Thus, a satisfactory progressive picture isobtained unless the encoding is difficult.

In the case of a movie, which contains a progressive picture of 241frames, a sufficient picture is obtained by the PSDM system. The systemshown in FIG. 61 is basically the same as those shown in FIGS. 22 and23. In the latter half of the production of the disk, a sum signal isrecorded in the basic stream with a basic stream identifier being addedthereto in an authoring section, and a difference signal is recorded ina provider defined stream with a provider defined stream identifierbeing added thereto. In the case of a movie, a 3-2 transform identifiersynchronized with the sum and difference signals is added.

The reproduction apparatus decodes the sum signal from a packet providedwith the basic stream identifier 267 by a first decoder 69 a, anddecodes the difference signal from a packet provided with the providerdefined stream identifier 268. Signals A and B are obtained by a sumcalculation section 250 and a difference calculation section 251. Thus,a 525P signal is synthesized.

FIG. 62 shows a system for dividing a wide 525P signal in a horizontaldirection and PSDM-recording the resultant signal as two interlacesignals, like in FIG. 58.

With reference to FIG. 26 and part (3) of FIG. 35, a process forreproducing the optical disk 155 and switching the first video signal tothe second video signal at t=tc will be described. As shown in FIG. 26,the optical disk 155 (provided as an example of an optical medium) hasfour channel stream recorded by an interleave system. The streams arerecorded in the order of A1, B1, C1, D1, A2, B2, C2, D2, A3, B3, C3 andD3 in interleave units of 1 GOP. Since the first video signal is firstoutput, interleave blocks (herein after, referred to simply as “ILB”) 84a and 84 b (i.e., A1 and B1) are continuously reproduced and a trackjump 156 is performed, thus reproducing ILBs 84 e and 84 f (i.e., A2 andB2). When the first video signal is switched to the second video signalat t=tc, a track jump 157 is performed, thus reproducing ILBs 84 i and84 h (i.e., C3 and D3). Thus, A1, A2 and C3 as main signals and B1, B2and D3 as sub signals are reproduced, extended by the extension section,and sent through the synthesis section 101 b to the output section 110b. The resultant signal is synchronized with a sub picture signal from asub picture decoder 159 and an audio signal from an audio signalreproduction section 160 by the AV synchronization section 158. Thus,these signals are output with matching timing. Accordingly, theprogressive signal in the first stream and the progressive signal in thesecond stream are reproduced seamlessly with no disconnection. A methodfor synchronization for providing a seamless reproduction will bedescribed later.

With reference to FIG. 45, a method for synchronizing two picturesignals and an audio signal when two streams are simultaneouslyreproduced as in the case of, for example, a 3D picture or scope picturewill be described. When three or four streams are simultaneouslyreproduced as in the case of a 720P signal, a similar method is usableand will not be described.

First, a method for synchronizing two streams according to the presentinvention will be described. First, as shown in FIG. 39, a systemreproduced from the optical disk is once accumulated in a track buffer23 and then sent to a first video decoder 69 d and a second videodecoder 69 c. In the track of the optical disk, a first stream A and asecond stream of the progressive signal are alternately recorded on aninterleave block-by-interleave block basis.

First, the stream A is reproduced at 2× rotation, and data accumulationin a first track buffer 23 a of the track buffer 23 is started. As shownin part (1) of FIG. 45, when t=t1 to t2, data for 1 interleave block(ILB) I1 of the first video signal for 1 interleave time T1 isaccumulated. A first track buffer data amount is increased, and becomesequal to 1 ILB at t=t2. Thus, data accumulation for 1 ILB of the firstvideo signal is completed. At t=t2, after accumulation of data for 1 ILBof the first video signal corresponding to 1 GOP or more is completed,the second video signal (stream B) is reproduced from the optical diskstarting from the interleave block I2. As shown in the solid line inpart (4) of FIG. 45, data accumulation of the second video signal in asecond track buffer 23 b is started at t=t2 and continued until t=t6.From t=t2 through t8, as shown in parts (7) and (10) of FIG. 45, thevideo presentation stamps (VPTS) of the first video signal and thesecond video signal are synchronized and respectively sent to the firstvideo decoder 69 c and the second video decoder 69 d from the trackbuffer 23 a and the track buffer 23 b. As shown in parts (8) and (11) ofFIG. 45, the input signals are output as two pieces of video data afterbeing extended by the first and second video decoders 69 c and 69 d. Theoutput of these pieces of data starts at t=t3, which is delayed by avideo delay time period twd, which is required for MPEG extension of thedata. From t=t4 through t10, the streams A and B are synthesized into aprogressive signal by a progressive transform section 170. Thus, aprogressive signal for one interleave block is output.

As described above, from t=t2 through t8, data for one interleave blockis input to the decoders. Accordingly, the data in the first trackbuffer 23 a and the data in the second track buffer 23 b are consumedand reduced at substantially the same rate. Therefore, as shown in part(2) of FIG. 45, the data amount in the first track buffer is reducedfrom t=t2 through t7. At t=t7, the data amount is ½ of 1 ILB. Since datareproduction for the interleave block I5 starts at t=t7, the data amountincreases until t=t8, when the data amount reaches 1 ILB. Since datainput to the first decoder 69 c starts at t=t8 as at t=t2, the dataamount reduces until t=t11. Finally, the buffer memory amount becomes ½ILB.

With reference to part (4) of FIG. 45, a change in the memory amount inthe second track buffer 23 b for stream B will be described. At t=t2,input of data B1 for the interleave block I2 of stream B in the secondtrack buffer 23 b starts. At the same time, transfer of data B1 to thesecond video decoder 69 d starts. Accordingly, the buffer amount at t=t6is ½ ILB. When 2-angle recording of a progressive signal according tothe present invention is performed, it is necessary to perform a trackjump to the interleave block I5 over the interleave blocks I3 and I4since there are four streams, i.e., four interleave blocks. During thejump period 197 (tj), data input from the optical disk is interrupted.Thus, the buffer amount of the stream B is reduced until t=t8, when thebuffer amount is close to zero.

Since input of data B2 of the interleave block I6 starts at t=t8, thebuffer amount starts increasing again. At t=t11, the memory amount ofthe second track buffer is ½ ILB. At t=t11, a track jump to theinterleave block I9 of A3 over the interleave blocks I7 and I8 isperformed.

The above-described operation is repeated.

Now, the minimum necessary memory capacity for a track buffer 23 (totalcapacity of the first and second track buffers 23 a and 23 b) accordingto the system of the present invention will be checked. A track buffercapacity 198 indicated by dotted line in part (4) of FIG. 45 shows thetotal data amount in the first and second track buffers 23 a and 23 b. Acontinuous reproduction is realized by setting the total capacity of aminimum 1 ILB in the track buffer.

According to the present invention, the total capacity of the trackbuffers 23 a and 23 b is set to be 1 interleave block or more forprogressive reproduction. Thus, overflow and underflow of the trackbuffer are prevented. A method for switching the system clock STCbetween two streams will be described with reference to FIG. 31. Aprogressive signal includes two streams A and B. Here, the streams oftwo interlace signals forming a 1 ILB progressive signal are referred toas A1 and B1. As shown in part (1) of FIG. 31, data A1 for stream A isreproduced during the ½ ILB time period and all the data is recorded inthe buffer. Then, as shown in part (2) of FIG. 31, data for stream B isreproduced as B1 and stored in the buffer after A1 is reproduced. Sincethe data reproduced from the optical disk is restricted with stream B(part (2) of FIG. 31) as described above, the track buffer does notoverflow. Stream A (part (3) of FIG. 31) or stream clock (SCR) from thetrack buffer for stream B is reset substantially in synchronization withthe start J of the reproduction of stream B (part (2) of FIG. 31). Sincestream B is output at the speed of 2×, the stream clock is counted atthe speed of 1× as shown in part (3) of FIG. 31, i.e., at half the speedof stream B due to the buffer. At point G, the stream clock is reset.Time VPTS2 at which the video signal for stream B is output needs to besynchronized with time VPTS1 in consideration of the delay time periodTvd due to, for example, MPEG decoding time period. In this case, atpoint I (t=Ti), when the VPTS stops rising, AV synchronization controlis restarted. By checking VPTS2 of stream B and synchronizing VPTS1 ofstream A to VPTS2, synchronization is realized by one-system simplecontrol. VPTS1 can be used additionally.

Audio data of synchronizing stream B is reproduced and the system clockis switched at point H using APTS of stream B as shown in part (4) ofFIG. 31. Regarding a sub picture signal of stream B, the system clockcan be switched in a similar manner.

By using data of stream B with priority, AV synchronization is realizedwith simple control.

All the data in streams. A1 and A2 is stored in the buffer memory, thebuffer memory does not overflow. Stream B1 may possibly overflow.However, according to the present invention, the synchronization controlis performed using stream B and the system clock is switched to controlthe signal flow so that VPTS2 does not exceed the VPTS threshold levelas shown in part (6) of FIG. 31. Therefore, the buffer does notoverflow.

According to the present invention, the audio signal of stream B is usedfor audio reproduction. Therefore, the buffer amount of audio decoder isreduced to ½. Furthermore, by the system clock is switched at point H(t=Th) as shown in part (4) of FIG. 31, the audio signal is reproducedsmoothly without exceeding the APTS threshold level. The sub pictureinformation is also reproduced with smooth synchronization. Accordingly,picture, audio and sub picture (subtitles or the like) signals aresynchronized, and picture and audio are reproduced seamlessly. The audiosignal and the sub picture signals of stream A can be omitted. In theembodiment where the audio and sub picture signals are put into stream Bso that stream B2 is reproduced by an existing reproduction apparatus,and reproduction of stream A is controlled by the second video signaloutput control information provision section 179; a picture with noaudio signal is prevented from being output. By omitting the audio andsub picture data of stream A, progressive picture software, for example,a 2-hour movie, can be recorded in one two-layer disk by the interleaveblock recording system according to the present invention. Such aneffect will be described. In the case of a movie, data for about 2 hoursand 15 minutes can be recorded on a one-layer 4.7 GB DVD. In order toperform 2-channel recording of a progressive picture without finding adifferential, 9.4 GB is required. A picture signal requires 4 Mbps, andsub picture and audio signals require almost 1 Mbps. When the audiosignal of 1 Mbps is recorded in one stream, a total of only 9 Mbps issufficient. In other words, only 90% of the data amount, i.e., 8.5 GB(90% of 9.4 GB) is sufficient. Therefore, a two-layer disk accommodatesthe data for one layer and a progressive signal.

The synchronization method of the present invention functions asfollows. Where an interleave block of stream A is recorded first andthen an interleave block of stream B is recorded on the optical disk,when the first data (e.g., stream A) is stored in a track buffer and thenext data (e.g., stream B) is reproduced, the synchronizationinformation of stream B is mainly used. Specifically, the system clockis switched so that the video time stamp of stream B (VPTS2) does notexceed the threshold value of VPTS2. In this manner, video and audiosignals are reproduced in synchronization with each other with nodisconnection. Stream A can be read from the buffer in synchronizationwith the time information such as VPTS2 (time stamp of stream B). Thus,the control is simple.

As described above, according to the present invention, the first streamis once accumulated in a buffer and only the second stream is processedwith synchronization. Thus, the control is accurate and simple. Overflowand underflow can be prevented by setting the size of the buffer memoryto be 1 ILB or more.

An existing DVD reproduction apparatus uses a 100 to 300 kB buffermemories, which is about ⅕ of the standard 1 ILB. According to thepresent invention, smooth reproduction is performed with the standard 1ILB buffer memory. 1 ILB corresponds to 0.5 to 2 seconds. Since the waittime period in the case of multiple angle reproduction can be only about1 second, 1 ILB is actually considered to correspond to 0.5 to 1 second.In order to handle an 8 Mbps stream corresponding to 1 second, a buffermemory of 1 MB or more is usable in the reproduction apparatus accordingto the present invention.

The synchronization control section 166 in FIG. 30 can switch the systemclock using the synchronization data regarding the interleave blocks I2and I6 of the second video signal to realize seamless reproductionbetween interleave blocks. During data reproduction for interleaveblocks I2 and I6, the motor rotation speed reproduction track iscontrolled while monitoring the buffer amount of stream B. Thus, thememory amounts of the track buffers 23 a and 23 b can be optimized so asnot to overflow. All the data for the interleave blocks I2 and I6 ofstream A is in the track buffer 23 a and is not suitable to optimize thebuffer size. When audio data of the interleave blocks I1 and I5 is usedfor reproduction, it is required to accumulate the one interleave blockor more of audio data and sub picture data in the track buffer 23 (FIG.39) and the audio decoder buffer 172 (FIG. 39) as shown in part (3) ofFIG. 45 in order to match the time stamp of the audio data with the timestamp of the video output of parts (8) and (11) of FIG. 45. By contrast,when the audio data of the interleave blocks I2 and I6 is used, ½ ILBdata is sufficient as shown in part (5) of FIG. 45. Accordingly, therequired memory amount of the track buffer 23 (FIG. 39) and the audiodecoder buffer 172 (FIG. 39) is reduced to half.

As shown in FIG. 45, for reproducing data of interleave blocks I1 and I2including the main signal of a progressive signal and data of interleaveblocks I5 and I6 including the interpolation of the progressive signal,the interleave blocks I5 and I6 can be stored in the buffer and then themotor rotation can be controlled based on the reproduction dataregarding the interleave blocks I2 and I6. Thus, the memory amount ofthe buffer is reduced. The system clock of the AV synchronizationcontrol section 158 in FIG. 30 can be switched based on the system clockof the interleave blocks I2 and I6. Thus, stable decoding is realizedwithout causing the buffer to overflow.

The method of skipping the first field of a VOB of a progressive signalis described with reference to FIG. 37. A second practical method iscarried out with the recording apparatus 99 shown in FIG. 22. Among anOdd First identifier 199 obtained by interlace transform and an EvenFirst identifier 200, only the Even First identifier 200 is transformedby an Even/Odd transform section 201 into an Odd First identifier 202and provided to each piece of MPEG data. Thus, all the VOBs start withan Odd First identifier.

As shown in FIG. 21, the reproduction apparatus reproduces the dataregarding the Odd First identifier 199 and the data regarding the OddFirst identifier 202 obtained from the Even First identifier. In step203, it is checked whether or not a progressive signal is reproduced. Ifyes, in step 204, the Odd First identifier of the second video signal istransformed into an Even First identifier 200 a and sent to theinterlace transform section 71 b of the MPEG decoder. If no, theidentifier is not transformed. The interlace transform section 71 boutputs the field of the frame picture of the second video signal first.Thus, an Even First picture is output. The synthesis section 90synthesizes the Even First picture of the second video signal and theOdd First picture of the first video signal and outputs a normalprogressive picture. By this method, all the interleave blocks startwith an Odd First picture, and thus seamless multiple angles arereproduced with no problem by a DVD reproduction apparatus. Since eachinterleave block is restricted to start with an Odd First picture forseamless multiple angle reproduction, the dummy field need not beinserted. Thus, the recording efficiency is not reduced.

According to the second method of even/odd transform, the first videosignal is normally reproduced even with an existing reproductionapparatus. However, when interlace transform is performed in accordancewith the Odd First identifier of the second video signal by the existingreproduction apparatus, the odd field and the even field are inverted.Thus, a low quality picture with a lower resolution is output. In orderto avoid this, when a conventional reproduction apparatus is used,information regarding the restriction on the reproduction of the secondvideo signal by the DVD format is recorded on the optical disk 85 by thesecond video signal output restriction information provision sectiondescribed with reference to FIG. 40. Thus, the second video signal isnot reproduced by the existing reproduction apparatus, and the situationwhere the user views unpleasant picture is avoided.

With the recording apparatus, an Odd First picture (field picture) and atransformed Odd First picture (field picture), both of which are fieldpictures, are compressed respectively by compression sections 81 a and81 b by variable encoding. When motion detection and compensation areperformed separately, encoding of a picture which is difficult tocompress results in separate block distortions. When such encodedsignals are synthesized into a progressive signal, the decoded pictureis deteriorated with noise. In order to avoid this, motion detectioncompensation is performed with an identical motion vector by one motiondetection/compensation section 205 for encoding. Such processing matchesthe block distortion when the two fields are decoded. The matched blockdistortion is less conspicuous. Furthermore, the load for encoding isreduced.

Next, an operation of the AV synchronization section 158 will bedescribed in detail.

The AV synchronization section is one of the most important sections ofthe present invention.

First, an operation of a system control section in FIG. 5 will bedescribed. The system control section 21 determines whether or not anoptical disk has been set (inserted) in the reproduction apparatus. Oncethe optical disk is detected to be set, the system control section 21controls a mechanism control section and a signal control section tocontrol the disk rotation until stable reading is performed. When thestable reading is performed, the optical pickup is moved to read avolume information file shown in FIG. 28.

The system control section 21 further reproduces a program chain groupfor a volume menu in accordance with volume menu management informationin the volume information file shown in FIG. 28. When the program chaingroup for the volume menu is reproduced, the user can designate datanumbers of desired audio data and sub picture data. Reproduction of theprogram chain group for the volume menu during the reproduction of thedata on the optical disk can be omitted when it is not necessary for thespecific use of the multi-media data.

The system control section 21 reproduces and displays a program chaingroup for a title menu in accordance with title group managementinformation in the volume information file. Thus, the system controlsection 21 reads the file management information of the video fileincluding the title selected based on the user's selection and isdirected to the program chain at the start of the title. The programchain group is reproduced.

FIG. 29 is the flowchart showing a detailed process of reproduction ofthe program chain group performed by the system control section 21. Asshown in FIG. 29, in steps 235 a, 235 b and 235 c, the system controlsection 21 reads corresponding program chain information from the volumeinformation file or a program chain information table of the video file.When the program chain is not completed in step 235 d, the processingadvances to step 235 e.

In step 235 e, it is determined whether or not the current cell and theimmediately previous cell should be connected seamlessly referring toseamless connection instruction information for the cell to betransferred next in the program chain information. If yes, theprocessing goes to step 235 f for seamless connection processing. If no,ordinary connection is performed.

In step 235 f, the mechanism control section and the signal processingsection, for example, are controlled to read DSI packets, so that VOBreproduction end time (VOB_E_PTM) in the DSI packet of the cell whichhas been transferred and VOB reproduction start time (VOB_S_PTM) in theDSI packet of the cell to be transferred next are read.

In step 235 h, “VOB reproduction end time (VOB_E_PTM)-VOB reproductionstart time (VOB_S_PTM)” is found. The resultant value is sent to the STCoffset synthesis section 164 in the AV synchronization control section158 in FIG. 30 as an STC offset value between the current cell and theimmediately previous cell which has been transferred.

Simultaneously, in step 235 i, VOB reproduction end time (VOB_E_PTM) istransferred to an STC switch timing control section 166 as switchingtime T4 for an STC switch 162 e.

The system control section 21 then instructs the mechanism controlsection to continue reading data until the terminal position of thecurrent cell. Thus, the data for the current cell is transferred to thetrack buffer 23 in step 235J. Upon completion of the transfer, theprogram chain information is read in step 235 c.

If it is determined a seamless connection is not necessary in step 235e, the data is transferred to the track buffer 23 until the end of thesystem stream, and then program chain information is read in step 235 c.

Hereinafter, two examples of a method for AV synchronization control forseamless connection and seamless reproduction will be described. Inother words, the AV synchronization control section 158 shown in FIGS.26 and 39 will be described in detail.

Referring to FIG. 39, a system decoder 161, an audio decoder 160, videodecoders 69 c and 69 d, and a sub picture decoder 159 are allsynchronized to a system time clock given by the AV synchronizationcontrol section in FIG. 30 to process the data in the system stream.

Regarding a first method, the AV synchronization control section 158will be described with reference to FIG. 30.

In FIG. 30, the AV synchronization control section includes STC switches162 a, 162 b, 162 c and 162 d, an STC 163, an STC offset synthesissection 164, an STC setting section 165 and an STC switch timing controlsection 166.

The STC switches 162 a, 162 b, 162 c, 162 d and 162 e switch between anoutput value of the STC 163 and an output value of the STC offset valuesynthesis section 164 as a reference clock to be provided to the systemdecoder 161, the audio decoder 160, the main video decoder 69 c, the subvideo decoder 69 d and the sub picture decoder 159, respectively.

The STC 163 is a reference clock of the entire MPEG decoder shown inFIG. 39 in ordinary reproduction.

The STC offset synthesis section 164 continues outputting a valueobtained by subtracting the STC offset value provided by the systemcontrol section from the value of the STC 163.

The STC setting section 165 sets an STC initial value given by thesystem control section or an STC offset synthesis value given by the STCoffset synthesis section 164 in the STC 163 at the timing given by theSTC switch timing control section 166.

The STC switch timing control section 166 controls the STC switches 162a through 162 e and the STC setting section 165 based on STC switchtiming information given by the system control section, the STC 163, andthe STC offset synthesis value given by the STC offset synthesis section164.

The STC offset value is an offset value used for changing the STC valuewhen system stream #1 and system stream #2 having different STC initialvalues are continuously reproduced.

The STC offset value is specifically obtained by subtracting the “VOBreproduction start time (VOB_S_PTM)” described in the DSI of systemstream #2 to be reproduced next from the “VOB reproduction end time(VOB_E_PTM)” described in the DSI of system stream #1 reproduced first.The information regarding the display of such a value is pre-calculatedby reading data from the optical disk in FIG. 5 by the system controlsection 167 when the data is input to the track buffer 23.

The calculated offset value is supplied to the STC offset synthesissection 164 before the last pack of system stream #1 is input to thesystem decoder 161.

Except for seamless connection control, the data decoding processingsection 165 in FIG. 5 operates as an MPEG decoder. The STC offset valuegiven by the system control section 21 is 0 or an arbitrary value. TheSTC switches 162 a through 162 e always is selected to be connected tothe STC 163.

With reference to FIG. 38, switching of the STC switches 162 a through162 e in the connection part of the system control section and anoperation of the STC 163 when two system streams having non-continuousSTC values, such as system streams #1 and #2, are continuously input tothe system decoder 161 will be described.

The SCR, APTS, VPTS and VDTS of the system streams #1 and #2 to be inputwill not be described.

In the STC 163, an initial STC value corresponding to system stream #1which is being reproduced is set by the STC setting section 165, and thevalue is sequentially counted up in accordance with the reproduction.The system control section 167 (FIG. 5) calculates the STC offset valueby the above-described method and sets this value in the STC offsetsynthesis section 164 before the last pack of system stream #1 is inputto the decoder buffer. The STC offset synthesis section 164 continuesoutputting a value obtained by subtracting the STC offset value from thevalue of the STC offset 163.

The STC switch timing control section 166 obtains time T1, at which thelast pack of system stream #1 reproduced first is input to the decoderbuffer, and switches the STC switch 162 a to the output side of the STCoffset synthesis section 164 at time T1 (step 168 b).

Thereafter, the STC value referred to by the system decoder 161 isprovided with an output from the STC offset synthesis section 164. Thetransfer timing of system stream #2 to the system decoder 161 isdetermined by the SCR described in the pack header of system stream #2.

Next, the STC switch timing section 166 obtains time T2, at which thereproduction of the last audio frame of system stream #2 is terminated,and switches the STC switch 162 b to the output side of the STC offsetsynthesis section 164 at time T2 (step 168 c) at time T2. A method forobtaining time T2 will be described later.

Thereafter, the STC value referred to by the audio decoder 160 isprovided with an output from the STC offset synthesis section 164. Theoutput timing of system stream #2 is determined by the APTS described inthe audio packet of system stream #2.

Next, the STC switch timing section 166 obtains time T3 and T3′, atwhich the decoding of the last video frame of the main signal and thesub signal of system stream #1 reproduced first is terminated, andswitches the STC switches 162 c and 162 d to the output side of the STCoffset synthesis section 164 at time T3 and T3′ (step 168 d). A methodfor obtaining time T3 will be described later. Thereafter, the STC valuereferred to by the video decoders 69 c and 69 d is provided with anoutput from the STC offset synthesis section 164. The video decodingtiming of system stream #2 is determined by the VPTS described in thevideo packet of system stream #2. Next, the STC switch timing section166 obtains time T4, at which the reproduction output of the last videoframe of system stream #1 reproduced first is terminated, and switchesthe STC switch 162 e to the output side of the STC offset synthesissection 164 at time T4 (step 168 e). A method for obtaining time T4 willbe described later.

Thereafter, the STC value referred to by the video output switch 169 andthe sub picture decoder 159 is provided with an output from the STCoffset synthesis section 164. The video output timing and sub pictureoutput timing of system stream #2 are determined by the VPTS and SPTSdescribed in the video packet and the sub picture packet of systemstream #2.

When switching of the STC switches 162 a through 162 e is completed, theSTC setting section 165 sets the value given by the STC offset synthesissection 164 in the STC 163 (step 168 f) (referred to as “reloading ofthe STC 163) and switches all the switches 162 a through 162 e to beconnected to the STC 163 (step 168 g).

Thereafter, the STC value referred to by the audio decoder 160, thevideo decoders 69 c and 69 d, the video output switch 169 and the subpicture decoder 159 is provided with an output from the STC 163, and theoperation returns to the ordinary operation.

Now, two means for obtaining time T1 through T4 for switching the STCwill be described.

According to first means, information representing time T1 through T4,which can be easily calculated when the streams are created, is recordedon the disk. The system control section 21 reads the information andsends the information to the STC switch timing control section 166.

Especially as T4, “VOB reproduction end time (VOB_E_PTM)” described inthe DSI is used as it is.

On the disk, the value obtained based on the STC value used in systemstream #1 reproduced first is described, and the STC switch timingcontrol section 166 switches the STC switches 162 a through 162 e at themoment the value of the STC 163 becomes time T1 through T4.

According to second means, based on the timing when the leading data ofsystem stream #1 is written in the track buffer 23, the video decoderbuffers 171 and 171 a, and the audio decoder buffer 172, the time forreading the leading data is obtained.

Assuming that the track buffer 23 is a ring buffer including a writingpointer, a reading pointer and a data memory, the system control section21 specifically reads an address indicated by the writing pointer and anaddress indicated by the reading pointer. Based on an address indicatedby the writing pointer and an address indicated by the reading pointerwhen a target pack is written, the system control section 21 detects themoment when the pack written immediately before is read.

When reproduction of system stream #1 is completed and reproduction ofsystem stream #2 is started, the system control section 21 indicates theleading address of system stream #2 on the optical disk for reading.Accordingly, the system control section 21 learns the moment when theleading data of system stream #2 is stored in the track buffer 23. Next,time T1 is obtained by marking the address where the leading pack ofsystem stream #2 is written and setting the moment when reading of theimmediately previous pack is completed as Ti.

The moment T1 is obtained, the system control section 21 informs T1 tothe video decoders 69 c and 69 d and the audio decoder 160. Thus, thevideo decoders 69 c and 69 d and the audio decoder 160 learn that theleading packet of system stream #2 will be transferred to the videobuffer 171 and the audio buffer 172 thereafter.

Accordingly, the two video decoders 69 c and 69 d and the audio decoder160 learn the moment when the last packet of system stream #1 istransferred and obtain T2 and T3 by managing each decoder buffer in thesame manner as the buffer management of the track buffer 23.

In the case where T1 is detected, all the data has been read from thevideo decoder buffer 171 or audio decoder buffer 172 (immediately afterthe last frame of system stream #1 is decoded), and no data to bewritten has arrived (when the transfer time period between packs isempty), there is no data to be written. Thus, address management isimpossible. Even in this case, the packet of the frame to be decodednext before then next decoding timing (decoding timing of the leadingframe of system stream #2) is transferred without fail. Accordingly, theswitch timing is learned by setting the moment of transfer of the packetas T2 or T3.

Regarding T4, as described above, “display end time of last frame of thevideo of system stream #1 (VOB_E_PTM)” can be used as it is.

Next, a second method for seamless reproduction will be described.

FIG. 31 shows at which timing the system stream is reproduced and outputafter being input to the data decoding processing section in FIG. 38,passed through the decoder buffer and decoded. With reference to FIG.31, a change in each of APTS and VPTS values at the connection point ofsystem streams #1 and #2 will be described, and a method for AVsynchronization control at the seamless connection area during theactual stream processing will be described.

Then, with reference to the graph in FIG. 31, a method for performingseamless connection control in accordance with the process representedby the flowchart in FIG. 43 will be described.

The starting timing of the seamless connection control is as shown inpart (3) of FIG. 31 regarding SCR. While the SCR value in the graph isincreasing, system stream #1 is transferred from the track buffer 23(FIG. 5) to the data decoding processing section 16 (FIG. 5). Only atpoint G when the transfer of system stream #1 is completed and transferof system stream #2 is started, the SCR value is “0”. Accordingly, it isfound that new system stream #2 is input to the data decoding processingsection 16 by finding point G at which the SCR value is “0”. At thispoint (time Tg), the synchronization mechanism control section can turnoff (release) the AV synchronization mechanism of the reproductionoutput section.

It can be detected that the SCR value is “0” after the signal read fromthe optical disk is processed or written into the track buffer 23. TheAV synchronization mechanism can be turned off based on the detection atthis point.

In order to determine the timing at which AV synchronization mechanismonce turned off should be turned on (started) again, it is necessary toknow that both the audio output and the video output included in systemstream #1 have changed to the audio output and the video output of newsystem stream #2 to prevent inconsistent reproduction by which the audioand video signals do not match. The moment the audio output of theprevious system stream is changed to the audio output, new system stream#2 can be found by detecting point H at which the APTS value stopsincreasing. The moment the video output of the previous system stream ischanged to the video output, new system stream #2 can be found bydetecting point I at which the VPTS value stops increasing. Accordingly,the synchronization mechanism control section can restart the AVsynchronization at time T1, i.e., immediately after finding that point Hand point I both appear.

When the SCR value is not set in the SCR or the APTS value and VPTSvalue are directly compared with each other during the period from timeTg to time T1, the period in which the AV synchronization mechanism isof f can be further shortened.

In order to realize this, both the APTS value of the audio output dataand the VPTS value of the video output data from the data decodingprocessing section 16 are monitored, and the value which becomes lowerfirst is detected. At this point, i.e., time Th in FIG. 31, the AVsynchronization mechanism is turned off.

As is apparent, in order to perform the timing determination based onwhether the APTS and VPTS values continue increasing, the APTS and VPTSvalues need to be reduced at the point where the system streams areconnected. In other words, the last APTS and VPTS values in the systemstream need to be larger than the maximum initial values of APTS andVPTS in the system stream.

The initial APTS and VPTS values (ΔTad, ΔTvd in the figure) aredetermined as follows.

The initial APTS and VPTS values are each a sum of the time period inwhich video data or audio data is stored in the video buffer or audiobuffer and the reorder of the video (in MPEG pictures, the decodingorder and the display order of the pictures do not necessarily match,and display can be delayed by one picture at the maximum with respect tothe decoding). Accordingly, the sum of the time period required for thevideo buffer or audio buffer to become full and the display delay (oneframe) is the maximum initial value of APTS or VPTS.

The system stream can be created so that the last APTS and VPTS valuesin the system stream exceed such values.

In this example, the timing for turning on the AV synchronizationmechanism after the system streams are connected has been described tobe determined based on whether or not the APTS and VPTS values increase.The timing for turning on the AV synchronization mechanism can bedetermined using the threshold value as described below. First, audioand video threshold values shown in parts (4) and (5) of FIG. 31 aredetermined by the reproduction apparatus. These values equal to themaximum initial values of APTS and VPTS described above.

The timing is determined based on whether or not the APTS and VPTSvalues read by the APTS reading means and VPTS reading means arerespectively below the audio threshold value and video threshold value.When the APTS and VPTS values are larger than the audio and videothreshold values, data has not been changed to the data of the newsystem stream. When the APTS and VPTS values are equal to or smallerthan the audio and video threshold values, data output of the new systemstream has been started. Thus, the timing for turning on and off the AVsynchronization mechanism may be found.

The above-described on/off control of the AV synchronization mechanismprovides seamless reproduction which is not disturbed at the connectionarea of the system streams.

(Calculation of the Synthesis Section)

FIG. 98 illustrates in detail the calculation of the synthesis sectionof the reproduction apparatus shown in FIG. 21 and the divisioncalculation of the recording apparatus shown in FIG. 23.

Part (a) of FIG. 98 illustrates FIG. 23 in detail. Regarding the 525P orother progressive signal, a q'th line data 283 represented by A and a(q+1)th line data 284 represented by B are subjected to the calculationof (A+B)÷2 by a first division calculation section 141 of a divisioncalculation section 285, thereby obtaining a low frequency component M,which is set as the q'th line data of the first stream. In the case ofan interlace signal, lines 1, 3 and 5 are created in the p'th field. Inthe (P+1)th field, the (q+1)th line data, i.e., lines 2, 4 and 6 arecalculated on a line-by-line basis. The resultant interlace signal isencoded by a first encoder 82 a.

A second division calculation section 143 performs the calculation ofA-B. The DVD format and the like do not define a negative value. Inorder to realize compatibility with the conventional formats, (A−B)÷2 isadded to a constant 257 so that a negative value is not obtained. In thecase of 8-bit data, 128 is added as the constant 277. As a result of thecalculation, an interlace signal is created as the q'th line data 280(S). The interlace signal is encoded by a second encoder 28 b andrecorded on the disk by the MADM interleave system.

With reference to part (b) of FIG. 98, a calculation of the synthesissection of the reproduction apparatus shown in FIG. 21 will be describedin detail. As shown in part (a) of FIG. 98, the data multiplexed by theMADM system according to the present invention and recorded on the disk85 is divided into a first stream and a second stream, and processedwith decoders 88 a and 88 b to obtain two video signals. This signal isan interlace signal and a top line first signal (herein after, referredto as “TF”) in which the top line is an odd line. In the synthesissection 90, the calculation of (2M+2S−constant)÷2 is performed by thefirst calculation section 250, where M is the q'th line data of themaster signal and S is the q'th line data of the sub signal. As aresult, (A+B+A−B+256−256)÷2=A. The q'th line data (A) is obtained and isoutput as r'th line data 281 (output picture).

As shown in part (a) of FIG. 98, the constant 277 is added by the secondcalculation section 143. Accordingly, the original data is obtained bysubtracting the twice the value of the value (128) obtained bysynthesis, i.e., 256. Due to the compatibility, a conventional decoderin which negative values are not defined can be used.

Then, the calculation of (2M−2S+(2×constant)) is performed by a secondcalculation section 251. As a result, (A+B−A−B−256−256)÷2=B. The (q+1)thline data 284 is obtained and output as (r+1)th line data 282.

Thus, two interlace signals are synthesized, and a progressive videosignal having 480 lines (1st through 480th lines) is output.

The system shown in FIGS. 98, 21 and 23 has a feature that division andsynthesis can be conducted with only one adder and one subtractor for8-bit data and 10-bit data and thus the circuit structure is simplified.Thus, a high resolution picture with progressive and wide video signalsare obtained with no significant cost increase.

Since a negative value is reproduced simply by adding the constants 278a and 278 b to the A-B signal, the conventional decoders 279 and 280which cannot handle negative values are usable.

As shown in part (a) of FIG. 98, in both the first stream and the secondstream, the first line of the first field is an odd line (Top LineFirst; TF). According an encoder of the DVD format, fields are droppedunless the streams are Top Line First streams. Since each stream is aTop Line First stream according to the system of the present invention,fields are not dropped.

FIG. 96 shows an overall operation of the reproduction apparatus shownin part (b) of FIG. 98. A reproduction signal is divided by a divisionsection 87 in units of nGOP into a first stream and a second stream. Thefirst and second streams are decoded by first and second decoders 88 aand 88 b into two Top Line First (TF) streams. A Top Line First signal244 and a Bottom Line First signal 245 are created by the firstcalculation section 250 and the second calculation section 251. Then, ananalog signal such as 525P is output by a DA conversion section 266.

In FIG. 96, two field pictures having the same time stamp aresynthesized in a vertical direction. By synthesizing the pictures in ahorizontal direction according to the present invention, the horizontalresolution can be doubled. FIGS. 58, 59 and 60 show a recordingapparatus, and FIG. 20 shows a reproduction apparatus including a widepicture synthesis section 173. With reference to FIGS. 91 and 92, theprinciple of the division section of the recording apparatus and theprinciple of the wide picture synthesis section 173 of the reproductionapparatus will be described in detail.

FIG. 91 shows a method for dividing a luminance signal and a colorsignal in the left half. Luminance signals Y0 and Y1 of input pixelsignals 287 a and 287 b having a 1440 pixels in the horizontal directionare subjected to addition and subtraction respectively by a firstdivision calculation section 141 a and a second division calculationsection 141 b shown in FIGS. 91 and 92 of the division calculationsection 285 in FIG. 98. Thus, a luminance signal of (Y0+Y1)/2 of thefirst stream and a luminance signal of (Y0-Y1)/2 of the second streamare generated. The input signal having 1440 pixels in the horizontaldirection is divided into two video signals each having 720 pixels inthe horizontal direction. The first stream is passed through ahorizontal filter and thus deprived of a high frequency component.Accordingly, even when only the first stream is output on the screen bythe conventional apparatus, aliasing distortion does not occur. Thus,compatibility with the conventional apparatus is obtained. FIG. 92 showsprocessing of a color signal. An input pixel signal 287 a and an inputpixel signal 287 c with one input pixel signal interposed there betweenare used. From a signal Cb0 of input pixel signal 287 a and a signal Cb2of the input pixel signal 287 c, a sum signal (Cb0+Cb2)/2 is obtainedand set as a division pixel signal 290 a of the first stream. Adifference signal (Cb0-Cb2)/2 is set as a division pixel signal 291 a ofthe second stream. In a similar manner, (Ct0+Cr2)/2 and (Ct0−Cr2)/2 areobtained from input pixel signals 287 b and 287 d. From these signals,division pixel signals 290 b and 291 b of the first and second streamsare obtained. Thus, a high resolution signal having 1440 pixel in thehorizontal direction is divided into two NTSC-grade digital videosignals of the CCIR601 and SMPTE295M formats.

Next, the processing of the synthesis section 173 of the reproductionapparatus briefly described with reference to FIG. 20 will be describedin detail. In the synthesis section 90 in FIG. 91, division pixelsignals 288 b and 289 b of the first and second streams are addedtogether by the first calculation section 250 by the calculation of(Y6+Y7)/2+(X−Y+256)/2−128=Y6. Thus, the input pixel 287 g is obtained.Next, the difference calculation of (Y6+Y7)/2+(X6−Y7+256)/2+128=Y7 isperformed. Thus, the luminance signal of the input pixel 287 h isobtained. In this manner, a high resolution signal having 1440 pixels inthe horizontal direction is obtained from two signals each having 720pixels in the horizontal direction by a sum calculation and a differencecalculation.

Next, synthesis calculation of color signals will be described withreference to FIG. 92. In the case of the Cr signal, the division pixelsignals 290 d and 291 d of the first and second streams are subjected tosum calculation by the first calculation section 250 and differencecalculation by the second calculation section 251. Specifically, thecalculations of (Cr4+Cr6)/2+(Cr4−Cr6+256)/2−128=Cr4 and(Cr4+Cr6)/2−(Cr4−Cr6+256)/2+128=Cr6 are performed. Cr4 and Cr6 areobtained and assigned to input pixel signals 287 f and 287 h.

Regarding the Cb signals, similar calculations are conducted on thedivision pixel signals 290 a and 291 c. Cr4 and Cr6 are obtained andassigned to input pixel signals 287 e and 287 g. Thus, the luminancesignals and color signals of the input signal are completely synthesizedto obtain a high resolution signal having 1440 pixel in the horizontaldirection.

By the 2× reproduction apparatus, an interlace signal having 1440 pixelsin the horizontal direction is obtained. By the reproduction apparatusshown in FIG. 62, 3-2 transform is performed. In the case where a24-frames/sec. signal of a movie or the like is recorded, the24-frames/sec. signal is output a plurality of times by the frame memoryby the 3-2 transform section 174. Thus, a 60-frames/sec. progressivevideo signal is obtained. By doubling the horizontal resolution to 1440pixels, a wide 525P picture is obtained. Thus, a 1440×480P progressivepicture is output.

Thus, by combining the 3-2 transform section 174 and the wide picturesynthesis section 173, a 1440×480P high resolution progressive pictureis output from a 24P picture such as a movie even by the 2× reproductionapparatus. When such a picture is reproduced by an existing DVD player,only the sum signal of the first stream is reproduced, but horizontalinterlace interference does not occur since the picture is horizontallyfiltered.

With reference to FIG. 97, an operation of reproducing data on an MADMdisk will be described. On the MADM disk, a 60-frames/sec. progressivepicture is divided into two frames, i.e., an odd frame 294 and an evenframe 295. The operation of the division section 87 and the decodingsection 88 is the same as described with reference to FIG. 96 and willnot be described. In the time direction synthesis section 296, a firstfield 297 a and a second field 297 b of the first stream are synthesizedinto a first odd frame 294 a. A first field 298 a and a second field 298b of the second stream are synthesized into a first even frame 295 a.These frames are synthesized in the time direction in the order of thefirst odd frame 294 a, the first even frame 295 a, the first odd frame294 b, and the second even frame 295 b every 1/60 second. Thus, a60-frames/sec. progressive picture is reproduced. By the existing 1×reproduction apparatus, only the first stream is reproduced; i.e., a525P interlace signal is reproduced and the compatibility is realized.However, the motion is slightly unnatural since the picture is a30-frames/sec. picture. This system is an MADM system for recording two30-frames/sec. streams and has the effect of a high encoding efficiencyof the MPEG encoder due to the progressive picture.

(Optimization of Buffer Amount)

Regarding the total capacity of the track buffer circuit 23 in FIG. 5,it was described that data for at least one interleave block needs to beaccommodated in the track buffer circuit 23 in order to reproduce twostreams simultaneously as shown in FIG. 45. With reference to FIG. 87, abuffer amount required for the MADM system reproduction according to thepresent invention will be calculated. As the capacity of one interleaveblock, the values in FIG. 87 are obtained by calculation. FIG. 87 showsinterleave unit lengths required for 5000-sector and 10000-sector trackjumps with respect to each of transfer rates. The maximum transfer rateis 8 Mbps, and the maximum jump length is 10000 sectors. With theminimum of 551 sectors as the interleave unit length, a stable trackjump is realized for switching to an interleave unit of another streameven by a 1× drive. In actuality, a drive of more than 1× is used, andthus the length of 551 sectors is not necessary. In consideration of theworst case, the disk manufacturers record an interleave unit of 551 ormore sectors for an 8 Mbps stream. Accordingly, a buffer memory for oneinterleave unit is required by the MADM system according to the presentinvention as shown in FIG. 45. Stable simultaneous reproduction of twostreams is realized by setting a buffer memory of 551 sectors or moreand 1102 bytes or more.

(Switching Between Two Pieces of Reproduction Information)

FIGS. 93, 94 and 95 illustrate a system for maintaining thecompatibility by reproducing the same disk by a conventional apparatusand an apparatus according to the present invention.

FIG. 95 shows an operation of the conventional apparatus for reproducingan MADM system disk according to the present invention in part (a), andshows an operation of an MADM system apparatus for reproducing the MADMsystem disk in part (b).

An optical disk 1 a includes a plurality of (four in the figure) streamsrecorded in a divided manner. Accordingly, four interleave units 84 a,84 b, 84 c and 84 d having the same information on an n time period arerecorded on the optical disk 1 a in an order. Also on the optical disk 1a, a second reproduction information identifier 302 is recorded. Thesecond reproduction information identifier 301 indicates that firstreproduction information 300 for reproducing streams 1 and 3 and secondreproduction information 301 for reproducing streams 2 and 4 arerecorded on the optical disk 1 a.

As shown in part (c) of FIG. 95, the first reproduction information 300,300 a and 300 c has only leading address information regarding theinterleave blocks 84 a and 84 a corresponding to streams 1 and 3, i.e.,a pointer. The second reproduction information identifier 302 is notreproduced by an existing reproduction apparatus which does not considerreproduction of MADM data. Thus, the second reproduction informationidentifier 301 cannot be read or utilized effectively. Accordingly, theconventional apparatus operates as if only streams 1 and 3 are recorded.Streams 2 and 4 are not reproduced at all. A conventional reproductionapparatus reproduces, for example, only the left-eye information from anoptical disk having a 3D signal recorded in an MADM system. When 3Ddisplay is not conducted, display of a meaningless right-eye picture isprevented.

In the case of an optical disk having a high definition picture recordedin an MADM system, streams 1 and 3 have basic components, for example,NTSC. Streams 2 and 4 have a differential signal, i.e., color lessline-drawing. Since streams 2 and 4 are not reproduced by theconventional apparatus, it is prevented that the user views such anunpleasant picture. When such an MADM disk is reproduced by aconventional reproduction apparatus, a normal picture of streams 1 and 3is reproduced but an abnormal picture of streams 2 and 4 is notreproduced. Accordingly, complete compatibility is realized. Thisoperation will be described with a flowchart. As shown in FIG. 93, instep 303 a, an MADM disk having m streams is reproduced. Firstreproduction information 300 a has pointer information on streams 1 and3, i.e., the leading address of the interleave unit 84 e to be jumped tonext. The address information is used to conduct a track jump over aplurality of tracks as shown in FIG. 3 to access the leading address ofthe interleave block 84 e. The interleave block 84 e is the first blockamong the subsequent blocks in stream 1 having time information. Thus,data in stream 1 is continuously reproduced.

When an instruction to switch the stream is issued in step 303 b,whether there is an identifier showing the existence of a PCI table ispresent or not is checked in step 303 c. A DVD has a PCI identifier(non-seamless) showing the existence of the second reproductioninformation 301. An MADM disk has a DSI identifier (seamless) showingthe existence of the first reproduction information is recorded in lieuof the PCI identifier. When the disk is an MADM disk, the processingadvances to step 303 d to utilize the DSI table having the firstreproduction information. The first reproduction information has pointerinformation on only streams 1 and 3 in step 303 e. Therefore, in step303 f, a track jump is conducted based on the pointer information onstreams 1 and 3 to maintain the continuous reproduction mode of stream1. Alternatively, stream 1 is switched to stream 3, and reproduction isconducted continuously in terms of time but while skipping from data todata. As shown in step 303 g, an ordinary NTSC picture of streams 1 and3 is reproduced, but an unpleasant, unnecessary picture of streams 2 and4 is not output. Thus, complete compatibility is realized.

A process for simultaneously reproducing two streams out of streams 1,2, 3 and 4 by the MADM reproduction apparatus will be described withreference to FIGS. 94 and 95. As shown by second reproductioninformation 301, 301 a, 301 b, 301 c and 301 d in part (b) of FIG. 95,the interleave unit 84 a has leading address information of theinterleave unit 84 e, which is the next time information of streams 1,2, 3 and 4. Since a physical addresses of a sector of an arbitraryinterleave unit 84 e, 84 f, 84 g or 84 h is found, a track jump iseasily conducted. The reason is that the MADM reproduction apparatusreproduces the second reproduction information identifier 302, learnsthe existence of the second reproduction information, and utilizes thesecond reproduction information 301.

Thus, simultaneous reproduction of streams 1 and 2 or streams 3 and 4 isperformed, and reproduction of a 3D or high resolution signal from anMADM disk is realized. The second reproduction information identifier302 only needs to distinguish a conventional disk from an MADM disk, andcan be even 1-bit data. An MADM identifier indicating the existence of ahigh resolution signal or 3D signal can be used.

This operation will be described with reference to the flowchart in FIG.94. In step 304 a, an MADM disk is reproduced. In step 304 b, it ischecked whether there is a second reproduction information identifier302 or not, or whether there is an MADM high resolution/3D identifier ornot. If no, the disk is determined to be a conventional disk and theprocessing goes to step 304 h. If yes, the processing goes to step 304 cto check for the identifier of the interleave unit 84. If there is anidentifier showing the existence of the second reproduction information,or if there is a seamless identifier in the case of the DVD, theseamless identifier is interpreted as a non-seamless identifier. Thesecond reproduction information, which is not actually valid, isregarded as being valid in step 304 d. In step 304 e, link informationon steps 1, 2, 3 and 4 is extracted from the second reproductioninformation.

In step 304 f, first reproduction information, or a main stream which isswitchable from the DSI table in the case of the DVD, is detected. Inthe example shown in FIG. 95, streams 1 and 3 are found to be mainstreams. The first reproduction information includes main streaminformation, and the second reproduction information includes main andsub stream information. Accordingly, the main and sub streams can bedistinguished based on the first and second reproduction information. Inthe case of FIG. 95, the number of stream groups (angles) is found to be2 by checking the second reproduction information.

When an instruction to switch the stream (angles) is issued in step 304g, a switch from stream 1 to stream 3 is conducted in step 304 m. Forthis, simultaneous reproduction mode (A) for streams 1 and 2 usingpointer information on streams 1 and 2 of the second reproductioninformation is switched to simultaneous reproduction mode (B) forstreams 3 and 4. In other words, stepping access to the interleave units84 a, 84 b, 84 e and 84 f is switched to stepping access to theinterleave units 84 c, 84 d and 84 g. Thus, two-stream groups can beswitched in units of two streams.

Returning to step 304 h, when a seamless identifier indicating thesecond reproduction information is invalid is recorded on the disk, theconventional apparatus regards the second reproduction information (PCI)as being invalid in step 304 j. Thus, only streams land 3 are reproducedusing only the first reproduction information (DSI) in step 304 k.

As described above, by detecting either the conventional or the MADMidentifier, the second reproduction information which is not valid inaccordance with the conventional rule is regarded as being valid.Accordingly, a meaningless or unpleasant picture is not output from theMADM disk even by a conventional apparatus. Thus, the compatibility isimproved.

(2-Screen Simultaneous Reproduction)

With reference to FIG. 90, an operation of the 2-screen synthesissection 28 described with reference to FIG. 5 will be described indetail. Although n pieces of screens are used, the representation of2-screen is used in this specification. To the n-screen synthesissection 28 b in FIG. 90, a first picture (A) and a second picture (B) ofthe first stream, a first sub picture and a second sub picture areinput. In a simple structure, a line memory 28 c is included. In thiscase, line-synthesis of the first picture (A) 28 p and the secondpicture (B) 28 q results in a picture of mode 1L having two screens sideby side is obtained. Audio signals (A) and (B) of the first and secondstreams are synthesized by an audio mixer 28 f. In the case of mode 1L,only the audio signal (A) is output. In mode 2L, a first sub picture ofthe first stream is synthesized on the screen. Only one sub picture 28 rsuch as subtitles is selected and displayed by the n-screen synthesissection 28 b. This has an effect of enlarging the display. In mode 2L, asecond audio signal B is output after mixing to the speaker to the rightof the screen. Thus, the second audio signal 28 s of the second pictureB can be listened to at a low volume.

As a higher structure, a frame memory 28 d can be used. In this case,zooming of two screens is realized. A zoom signal generation section 28e which has received a zoom instruction signal 28 p sends a ratio changesignal to the n-screen synthesis section 28 band the audio mixer 28 f.When the first picture (A) is enlarged as shown in the 2-screen picture28 i in mode 1, the first audio signal is used. In an opposite case, thesecond audio signal is output as in the 2-screen picture 28 j. Thus, bychanging the ratio of the video signals and audio signals of the firstand second streams, video and audio can be matched. Pictures of streams3 through 6 can be displayed in a divided manner as shown in a 2-screenpicture 28 m.

As described above, in the embodiment where two streams aresimultaneously reproduced to output two video signals, and the synthesisof video signals and synthesis of audio signals are performed using the2-screen synthesis sections 28 and 28 b and the audio mixer 28 f, twostreams, for example, pictures taken by two cameras can be viewedsimultaneously.

(Alteration of the Filter)

According to the present invention, a video signal is divided into a lowfrequency component and a high frequency component by a picture divisionsection 141 a shown in, for example, FIG. 22. The division filter can berepresented as in FIG. 46. In FIG. 22, division calculation of the firststream is conducted by calculation parameters of m1=0, m2=½, m3=½, andm4=0. Division calculation of the second stream is conducted bycalculation parameters of m1=0, m2=½, m3=−½, and m4=0. Under theseconditions, a 525P progressive signal is divided into a low frequencycomponent and a high frequency component at the vertical resolution of250.

The dividing frequency of the border can be altered by changing thecalculation parameters of m1, m2, m3 and m4. As shown in FIG. 50, thedividing frequency can be changed from 200, to 250 and to 300, and eachfilter identifier 144 can be recorded on the optical disk. Thus, thefilter identifier 144 is detected by a filter identifier reproductionsection 305 of the reproduction apparatus in FIG. 96 during datareproduction, and the set values of calculation parameters of n1, n2, n3and n4 of the calculation section 212 a are changed by a calculationparameter output section 306 in accordance with the filter identifier inFIG. 50. The calculation section 212 a of the synthesis section 90performs calculation by the set values and processes vertical lines n−1,n, n+1 and n+2 based on the calculation parameters 196 of n1, n2, n3 andn4, thereby obtaining the n-line signal. This processing can be actuallyperformed in the first calculation section 250 and the secondcalculation section 251.

By changing the dividing frequency of the picture division filter, thedistribution of the data amount between the first and second streams canbe changed. In the case of the DVD format, the first and second streamseach have a maximum capacity of 8 Mpbs. When the dividing frequency isfixed, a picture having a high ratio of high frequency component causesthe second stream data to overflow, resulting in collapse of MPEGencoding signal in the high frequency range. A picture having a highratio of low frequency component causes the first stream data tooverflow, resulting in collapse of encoding to significantlydeteriorating the picture quality. In the case where the dividingfrequency is variable, when the high frequency component is excessive,the dividing frequency in FIG. 50 can be increased to 300. Thus, thesecond stream data amount is reduced and the first stream data amount isincreased. Thus, the distribution of the data is optimized, so that thecollapse of encoding is avoided.

When the low frequency component is excessive, the dividing frequencycan be decreased to 200. Thus, the first stream data amount is reduced,which avoids collapse. Collapse is usually avoided this way, and thevariable dividing frequency is effective. By changing the border of thedivision filter in accordance with the condition of the picture,collapse of encoding of one of the streams can be avoided. Accordingly,a satisfactory video signal is obtained. In other words, the overflow ofthe first or second stream is avoided by changing the division point, sothat recording and reproduction are performed with the data amount beingdistributed in a satisfactory manner.

(Scanning Line Transform)

An operation of a scanning line transform section 29 a described withreference to FIG. 5 will be specifically described. An MADM diskincludes both an area having a high resolution signal such as aprogressive signal and an area having a standard resolution signal suchas an NTSC signal. The two streams are reproduced simultaneously andindependently. The output is changed from progressive to NTSC or fromNTSC to progressive. When a signal is output from the output section 29b with no processing at the point of change, the scanning frequency ischanged from 31.5 kHz to 15.7 kHz. Therefore, the deflection frequencyof the TV 29 c is switched, thus disturbing the picture for a fewseconds. Even in a TV having a built-in line doubler, the picture isdisturbed when a progressive picture is switched to an NTSC picture.According to the present invention, this is avoided by automaticallyswitching the progressive signal by the output section 29 b. In moredetail, the NTSC picture of the first stream is scanned at 2× by thescanning transform section 29 a using an MADM disk identifier 10 hrecorded on the MADM disk 1 or the progressive signal is output as itis. Since the high resolution area for reproducing two streams isswitched to an ordinary resolution area for reproducing one stream, theoutput signal is immediately changed. Therefore, a progressive signal iscontinuously input to the TV 29 c. This system eliminates disturbancefrom the TV picture.

(Stream Switching Prohibiting Flag)

As a method for preventing a differential signal of a high resolutionsignal from being output in an existing apparatus, a method forrecording a stream switching prohibiting flag will be described.

As shown in FIG. 86, in step 307 a, a stream switching prohibiting flag309 is recorded on a disk 1 c. In step 307 b, stream 1 is set as theinitial stream value in the management information.

When the disk 1 c is set in an existing reproduction apparatus, in step307 a, management information for angle 1, i.e., stream 1 is read. Instep 307 f, angle 1 is reproduced. When an angle switch instruction isissued in step 307 g, an angle (stream) switching prohibiting flag ischecked in step 307 h. In an MADM disk, the angle (stream) is notswitched since the flag is recorded. Accordingly, the output of thedifferential picture is prevented and the compatibility is maintained.

(HDTV (1080i) Output)

A method for creating a 1080i picture to be output to an HDTV will bedescribed. In FIG. 20, a wide 525P picture is displayed as shown in thescope screen 178. The output is transformed into a progressive signalhaving 1050 lines by a line doubler. The progressive signal is furthertransformed into an interlace signal having 1050 lines by an interlacetransform section 175 b. That is, an interlace picture 178 b havingabout 1080 lines is obtained. Thus, output to the HDTV is realized.

(High Definition Audio Output)

In FIG. 20, a high definition audio signal is reproduced. In the case oflinear PCM, a range of 1.5 Mbps to 4 Mbps is required. In MADM, as shownin FIG. 88, a basic audio section 312 is recorded in stream 1 with 380kbps AC3, and a high definition audio section 313 is in stream 3. Anaudio recording identifier 314 is recorded as an MADM identifier. In thereproduction apparatus in FIG. 20, when an audio recording identifier314 is reproduced by an audio recording identifier reproduction section111, an audio signal is separated from the stream 2, and a highdefinition audio signal is reproduced by an audio decoder 160 a andoutput as an audio signal in the figure.

In the case of DVD, one stream has only a maximum of 8 Mbps. When a highdefinition audio signal which can have a maximum 4 Mbps is recorded intostream 1 which already has a basic picture, the basic picture isrestricted to only 4 Mbps and deteriorated in terms of quality. Thus,compatibility is not maintained. According to the present invention, theaudio signal is accommodated in streams 2, 3 and 4 as the highdefinition audio signals 313 a, 313 b and 313 c in FIG. 88. In thismanner, the high definition audio signals can be recorded withoutdeteriorating the quality of the basic picture. Especially, the dataamount of 525P differential signal in stream 2 is ½ to ⅓ of the basicpicture, and thus stream 2 still has about 4 Mbps. Even when thedifferential video signal and the high definition signal are recorded instreams 2 and 4 as the high definition audio signals 313 a and 313 b inFIG. 88, the high definition video and audio signals can be reproducedby a 2× reproduction apparatus without deteriorating the differentialsignal.

(Comparison Method of MADM Identifier)

As shown in FIG. 4, an MADM disk has an MADM identifier in managementinformation such as a TXT file. However, the TXT file may possibly havethe same data as the MADM identifier in error. When the non-MADM disk isreproduced as an MADM disk, malfunction occurs and an abnormal pictureis synthesized and output. In order to avoid such malfunction,authentification data for comparison is recorded according to thepresent invention.

As shown in FIG. 1, an authentification data generation section 315 isprovided. The MADM identifier 10 b and inherent attribute information316 of the disk (master disk) such as the title of the disk, disk ID,disk capacity, and final address value are calculated byauthentification data generation calculation section 316. Thus, MADMauthentification data 318 is generated. The MADM authentification data318 is recorded on the optical disk 1 together with the MADM identifier10 b and the authentification data 318 or progressive/3D arrangementinformation.

Then, the optical disk 1 is reproduced by the reproduction apparatus inFIG. 5 and compared by an MADM identifier comparison section 26 a.

The operation will be described in detail with reference to FIG. 9. TheMADM identifier comparison section 26 a reads the MADM identifier 10 b,the MADM authentification data 318, and the inherent attributeinformation 316 such as the title of the disk, disk number, capacity,and address from the optical disk 1, and compares the three types ofdata by the comparison calculation section 319. Only when it isdetermined that the data is correct by the determination section 320, aninstruction to reproduce the MADM disk by the MADM reproduction section321 is sent to the control section 21. Thus, the two streams aresynthesized to output a high resolution picture or a 3D picture. When itis determined that the data is incorrect by the determination section320, an instruction to perform ordinary reproduction by an ordinaryreproduction section 322 without MADM reproduction is sent.

In this manner, even when the same data as the MADM identifier 10 b isrecorded in the TXT file in error, the MADM reproduction apparatusperforms comparison using the comparison data. Accordingly, malfunctionis prevented. The authentification data and the MADM identifier can beone piece of data, or encrypted data of the MADM identifier and the diskattribution information can be recorded.

So far, applications of a system for reproducing and synthesizing aplurality of streams, i.e., an MADM system according to the presentinvention have been described. Hereinafter, MADM synchronization systemswill be described.

Example 2

The MADM system according to the present invention simultaneouslyreproduction of a plurality of streams. Synchronization methods areimportant. In the second through eighth examples, various methods ofsynchronization will be described. The MADM system is also applicable torecording and reproduction of high resolution pictures such as 3D or525P pictures, which will not be described below.

As an example, in the second example, an operation of a reproductionapparatus for reading data from an optical disk having three compressionvideo signals to be reproduced simultaneously and extending andreproducing the three compression video signals simultaneously will bedescribed.

FIG. 66 shows a data structure of the optical disk used in the opticaldisk reproduction apparatus in the second example.

Video signals A, B and C are MPEG-compressed to obtain compression videostreams A, B and C.

The compression video streams A, B and C are each packeted in units of 2kB into packets. A packet header of each packet includes a stream ID forindicating which one of the compression video streams A through C isstored. When the packet stores a leading part of the video frame, thepacket header also includes VPTS (video presentation time stamp) asvideo reproduction time information indicating the time to reproduce theframe. In the second example, an NTSC signal is used as the picturesignal, and the video frame cycle is about 33 msec.

On the optical disk, video packets created in the above-described mannerare grouped into, for example, compression video signals A-1, B-1 andC-1 each including an appropriate number of packets based on the datastored, and multiplexed.

FIG. 64 is a block diagram of the optical disk reproduction apparatus inthe second example.

In FIG. 64, the optical disk reproduction apparatus includes an opticaldisk 501 described above, an optical pickup 502 for reading data fromthe optical disk 501, signal processing means for performing a series ofsignal processing such as binarization, demodulation, and errorcorrection to the signal read by the optical pickup 502, a buffer memory504 for temporarily storing the data output from the signal processingmeans 503, division means 505 for dividing the data read from the buffermemory 504 into compression video signals, and reference time signalgeneration means 506 for generating a reference time signal 506including a counter (not shown) for counting 90 kHz clocks. Referencenumerals 510, 520 and 530 represent buffer memories for temporarilystoring the compression video signals divided by the division means 505.Reference numerals 511, 521 and 531 represent video decoders forextending and reproducing the compression video signals. Referencenumerals 512, 522 and 532 represent monitors for displaying the videosignals.

FIG. 65 shows the structure of each of the video decoders 511, 521 and531.

As shown in FIG. 65, the video decoder includes VPTS detection means 601for detecting a VPTS stored in the packet header of the video packet,video extension means 602 for MPEG-extending the compression videostream, and video reproduction timing control section 603 for comparingthe reference time signal and the VPTS and skipping or repeating thevideo reproduction on a frame-by-frame basis when the comparison resultexceeds the threshold value.

The optical disk reproduction apparatus shown in FIG. 64 operates in thefollowing manner.

The optical pickup is focus-controlled or tracking-controlled by servomeans (not shown) to read a signal from the optical disk 501 and outputsthe signal to the signal processing means 503. The signal processingmeans 503 subjects the signal to a series of processings includingbinarization, demodulation, error correction and the like. Then, thesignal processing means 503 stores the resultant signal in the buffermemory 504 as digital data.

The buffer memory 504 functions so that, even when the data supply fromthe optical disk 501 is temporarily stopped by, e.g., wait state, datasupply to the subsequent-stage sections is not stopped.

The data read from the buffer memory 504 is divided into compressionvideo signals A through C by the division means 505 and output. Thedivision means identifies which of the compression video signals Athrough C is stored in each packet with the packet ID in the packetheader of the packeted data, and determines the destination based on theidentification result.

The divided compression video signals are respectively stored in buffermemories 510 through 530.

The buffer memories 510 through 530 act to continuously supply data tothe video decoders 511 through 531.

The video decoders 511 through 531 read data from the buffer memories510 through 530 respectively, extend the compression signals, and outputthe signals as video signals to the monitors 512 through 532respectively.

With reference to FIG. 65, an operation of the video decoders 511through 531 will be described.

The compression video signal read from the buffer memory is input to theVPTS detection means 601 and the video extension means 602.

The video extension means 602 MPEG-extends the compression video streamand outputs the video signal.

The VPTS detection means 601 detects the VPTS of the packet header.

The video reproduction timing control means 603 receives the videosignal output from the video extension means 602, a reference timesignal and the VPTS output from the VPTS detection means 601, andcompares the reference time signal and the VPTS. When the differencebetween the two exceeds the threshold value, the video reproductiontiming is controlled so that the difference between the VPTS and thereference time signal is equal to or less than the threshold value.

In the second example, 33 msec is used as the threshold value. The videoreproduction timing control means 603 performs the following.

(reference time signal-VPTS)>33 msec.:1 frame is skipped.

(reference time signal-VPTS)<−33 msec.:1 frame is repeated.

In the second example, due to the precision error of the crystaloscillator used in the reference time signal generation means 506 andthe video decoders 511 through 531, the video decoders 511 and 531 areslower and the video decoder 521 is faster in terms of extension andreproduction with respect to the reference time signal. Unlessreproduction timing is corrected, the reproduced video signals are outof synchronization.

FIG. 67 is a timing diagram of video reproduction in the second example.Part (a) of FIG. 67 shows the reference time signal with respect toreproduction time t. Part (b) shows the VPTS#A, which is a VPTS of thecompression video signal A to be extended by the video decoder 511, part(c) shows the VPTS#B, which is a VPTS of the compression video signal Bto be extended by the video decoder 521, and part (d) shows the VPTS#C,which is a VPTS of the compression video signal C to be extended by thevideo decoder 531.

The video decoder 511 continues extension and reproduction of thecompression video signal A, and the difference between the VPTS#A andthe reference time signal exceeds 33 msec. as the threshold value at T1.Accordingly, the video reproduction timing control means of the videodecoder 511 skips one frame, which is originally to be reproduced, tocorrect the reproduction timing so that the difference between theVPTS#A and the reference time signal is equal to or less than thethreshold value.

The video decoder 521 continues extension and reproduction of thecompression video signal B, and the difference between the VPTS#B andthe reference time signal exceeds −33 msec. as the threshold value atT2. Accordingly, the video reproduction timing control means of thevideo decoder 521 reproduces one frame in repetition, which has beenalready reproduced, to correct the reproduction timing so that thedifference between the VPTS#B and the reference time signal is equal toor less than the threshold value.

Similarly, the video decoder 531 continues extension and reproduction ofthe compression video signal C, and the difference between the VPTS#Cand the reference time signal exceeds 33 msec. as the threshold value atT3. Accordingly, the video reproduction timing control means of thevideo decoder 531 skips one frame, which is originally to be reproduced,to correct the reproduction timing so that the difference between theVPTS#C and the reference time signal is equal to or less than thethreshold value.

As described above, in the second example, when the difference betweenthe reference time signal and the VPTS detected by each video decoderexceeds the threshold value, the video reproduction timing control meansof each video decoder performs correction so that difference between thereference time signal and the VPTS does not exceed the threshold value.In this manner, the pictures reproduced by video decoders can besynchronized with one another.

Example 3

The third example relates to a reproduction apparatus for correcting areference time signal using audio reproduction time informationindicating the time to reproduce the audio signal and synchronizes aplurality of video signals based on the reference time signal.

FIG. 70 shows a data structure of the optical disk used in the opticaldisk reproduction apparatus in the third example. The optical diskincludes compression audio data in addition to the data included in theoptical disk used in the second example.

An audio signal is audio-framed in units of 32 msec. for compression toobtain a compression audio stream. The audio stream is packeted in unitsof 2 kB into audio packets and recorded on the optical disk. A packetheader of each audio packet includes a stream ID for indicating that thestored data is a compression audio stream. When the packet stores aleading part of the audio frame, the packet header also includes APTS(audio presentation time stamp) as audio reproduction time informationindicating the time to reproduce the frame.

FIG. 68 is a block diagram of the reproduction apparatus in the thirdexample.

Elements 501 through 532 are the same as those shown in FIG. 64 in thesecond example.

Reference numeral 504 represents a buffer memory for temporarily storingthe compression audio signal. Reference numeral 541 represents audioextension means for extending the compression audio signal. Referencenumeral 542 represents a speaker for reproducing the extended audiosignal.

FIG. 69 shows a structure of the audio decoder 541. The audio decoder541 includes APTS detection means 701 for detecting an APTS stored in apacket header of the audio packet, and audio extension means 702 forextending the compression audio stream.

An operation of the optical disk reproduction apparatus shown in FIG. 68for reproducing the optical disk shown in FIG. 70 will be described.

The operation until the signal is input to the division means 505 issimilar to that with the optical disk reproduction apparatus in thesecond example.

The data read from the buffer memory 504 is divided into compressionvideo signals A through C and a compression audio signal by the divisionmeans 505 and output. The division means 505 identifies which of thecompression video signals A through C and the compression audio signalis stored in each packet with the packet ID in the packet header of thepacketed data, and determines the destination based on theidentification result.

The divided compression video signals and compression audio signal arerespectively stored in buffer memories 510 through 540.

The video decoders 511 through 531 read data from the buffer memories510 through 530 respectively, extend the compression video signals, andoutput the signals as video signals to the monitors 512 through 532respectively. The audio decoder 541 reads data from the buffer memory540, extends the compression audio signal, and outputs the signal as anaudio signal through the speaker 542.

The operations of the video decoders 511 through 531 for extending thecompression video signals and for correcting the synchronization whenthe difference between the reference time signal and the VPTS exceedsthe threshold value are the same as in the second example.

The compression audio signal read from the buffer memory 540 is input tothe audio decoder 541. APTS detection means 701 detects an APTS andoutputs. Audio extension means 702 extends the compression audio streamand outputs the audio signal.

The VPTS signal output from the audio decoder 541 is input to thereference time signal generation means 506, and the reference timesignal is corrected by the APTS.

In the third example, due to the precision error of the crystaloscillator used in the reference time signal generation means 506, thevideo decoders 511 through 531 and the audio decoder 541, the referencetime signal is faster in terms of extension and reproduction withrespect to the audio decoder 541. The video decoder 511 is slower andthe video decoder 521 is faster in terms of extension and reproductionwith respect to the reference time signal. Unless reproduction timing iscorrected, the reproduced video signals and audio signal are out ofsynchronization.

FIG. 71 is a timing diagram of audio reproduction in the third example.Part (a) of FIG. 71 shows the APTS with respect to reproduction time t.Part (b) shows the reference time signal. Part (c) shows the VPTS#A, atwhich the compression video signal A to be extended by the video decoder511 is to be reproduced, and part (d) shows the VPTS#B, at which thecompression video signal B to be extended by the video decoder 521 is bereproduced.

FIG. 71 does not show the VPTS#C, at which the compression video signalC to be extended by the video decoder 531, but the diagram is almost thesame as in FIG. 67 regarding the second example.

The reference time signal generation means 506 is corrected using theAPTS at time when the APTS shows ta1 and ta2, and the reference timesignal is reset as ta1 and ta2 at the respective time.

The video decoder 511 continues extension and reproduction of thecompression video signal A, and the difference between the VPTS#A andthe reference time signal exceeds 33 msec. as the threshold value at T4.Accordingly, the video reproduction timing control means of the videodecoder 511 skips one frame which is originally to be reproduced tocorrect the reproduction timing so that the difference between theVPTS#A and the reference time signal is equal to or less than thethreshold value.

The video decoder 521 continues extension and reproduction of thecompression video signal B, and the difference between the VPTS#B andthe reference time signal exceeds −33 msec. as the threshold value at T5and T6. Accordingly, the video reproduction timing control means of thevideo decoder 521 reproduces one frame in repetition which has beenalready reproduced to correct the reproduction timing so that thedifference between the VPTS#B and the reference time signal is equal toor less than the threshold value.

As described above, in the third example, when the difference betweenthe reference time signal and the VPTS detected by each video decoderexceeds the threshold value, the video reproduction timing control meansof each video decoder performs correction so that difference between thereference time signal and the VPTS does not exceed the threshold value.In this manner, the pictures reproduced by video decoders can besynchronized with one another.

Regarding the difference between the reference time signal and the APTS,the APTS is not corrected using the reference time signal but thereference time signal is corrected using the APTS. Accordingly, audioand video signals are synchronized with no unnaturalness in the audiooutput.

Example 4

The fourth example relates to a reproduction apparatus for correctingthe reference time signal using a VPTS detected by one video decoder andsynchronizing a plurality of video signals based on the reference timesignal.

FIG. 72 is a block diagram of an optical disk reproduction apparatus inthe fourth example.

Elements 501 through 532 are the same as those in the second example.Reference numeral 551 represents a video decoder used in the fourthexample.

The video decoder 551 has a function of outputting the detected VPTS.FIG. 73 shows a structure of the video decoder 551.

The video decoder 551 includes VPTS detection means 801 for detecting aVPTS indicating the reproduction time of the video signal multiplexed asthe compression video signal and video extension means 802 for extendingthe compression video stream.

In the fourth example, due to the precision error of the crystaloscillator used in the reference time signal generation means 506 andthe video decoders 521, 531 and 551, the reference time signal is fasterin terms of extension and reproduction with respect to the video decoder551. The video decoder 521 is slower and the video decoder 531 is fasterin terms of extension and reproduction with respect to the referencetime signal. Unless reproduction timing is corrected, the reproducedvideo signals are out of synchronization.

FIG. 74 is a timing diagram of video output in the fourth example. Part(a) of FIG. 74 shows the VPTS#A detected by the video decoder 511 withrespect to reproduction time t. Part (b) shows the reference timesignal. Part (c) shows VPTS#B, at which the compression video signal Bto be extended by the video decoder 521 is to be reproduced, and part(d) shows the VPTS#C, at which the compression video signal C to beextended by the video decoder 531 is to be reproduced.

The reference time signal generation means 506 is corrected using theAPTS at time when the APTS shows tv1 and tv2, and the reference timesignal is reset as tv1 and tv2 at the respective time.

The video decoder 521 continues extension and reproduction of thecompression video signal B, and the difference between the VPTS#B andthe reference time signal exceeds 33 msec. as the threshold value at T7.Accordingly, the video reproduction timing control means of the videodecoder 521 skips one frame which is originally to be reproduced tocorrect the reproduction timing so that the difference between theVPTS#B and the reference time signal is equal to or less than thethreshold value.

Similarly, the video decoder 531 continues extension and reproduction ofthe compression video signal C, and the difference between the VPTS#Cand the reference time signal exceeds 33 msec. as the threshold value atT8. Accordingly, the video reproduction timing control means of thevideo decoder 531 reproduces one frame in repetition which has beenalready reproduced to correct the reproduction timing so that thedifference between the VPTS#C and the reference time signal is equal toor less than the threshold value.

As described above, in the fourth example, when the difference betweenthe reference time signal and the values of VPTSs detected by the videodecoders 521 and 531 exceeds the threshold value, the video reproductiontiming control means of each video decoder performs correction so thatthe difference between the reference time signal and the VPTS does notexceed the threshold value.

By correcting the reference time signal using the VPTS#A detected by thevideo decoder 551, the video signal reproduced by the video decoder 551is not accompanied by any unnaturalness in the visual output due to theframe-by-frame skipping or repeated reproduction. Thus, the pictures canbe synchronized with one another.

Example 5

The fifth example relates to a reproduction apparatus including aplurality of video decoders for extending and reproducing a compressionvideo signal. Each of the video decoders includes reference time signalgeneration means. The reproduction apparatus corrects the reference timesignal of each video decoder using an APTS indicating the time toreproduce an audio signal to realize synchronization.

In the fifth example, the optical disk shown in FIG. 70 is used.

FIG. 75 is a block diagram of an optical disk reproduction apparatus inthe fifth example.

Elements 501 through 542 are the same as those shown in FIG. 68 in thethird example. Unlike the reproduction apparatus shown in FIG. 68, thereproduction apparatus in this example does not have reference timesignal generation means 506 independently, but each video decoder hasreference time signal generation means.

Reference numeral 561 represents a video decoder for extending andreproducing compression video signal A, reference numeral 571 representsa video decoder for extending and reproducing compression video signalB, and reference numeral 581 represents a video decoder for extendingand reproducing compression video signal C.

FIG. 76 shows a structure of each of the video decoders 561 through 581used in the fifth example.

The video decoder includes VPTS detection means 901 for detecting a VPTSindicating the reproduction time of the video signal multiplexed as thecompression video signal, video extension means 902 for extending thecompression video stream, and video reproduction timing control means903 for comparing the reference time signal and the VPTS and skipping orrepeating the video reproduction on a frame-by-frame basis when thecomparison result exceeds the threshold value, and reference time signalgeneration means 904 for generating the reference time signal.

In the fifth example, the reference time signal of reference time signalgeneration means 904 included in each of the video decoders 561 through581 is corrected using the APTS detected by the video decoder 541.

Since the reference time signals are corrected using the same APTS, thereference time signals generated in the video decoders 561 through 581show the same value after being corrected.

After the correction using the APTS, as in the third example, when thedifference between the reference time signal and the values of VPTSdetected by each video decoder exceeds the threshold value, the videoreproduction timing control means of each video decoder performscorrection by skipping or repeating the reproduction on a frame-by-framebasis so that difference between the reference time signal and the VPTSdoes not exceed the threshold value.

As described above, in the fifth example, the reference time signalgenerated in each video decoder is corrected with an APTS, and the videoreproduction timing control means of each video decoder maintains thedifference between each reference time signal and each VPTS to be equalto or less than the threshold value. Thus, the pictures can besynchronized with one another.

As in the third example, the audio signal and the video signal can besynchronized without providing any inconvenience in the audio output.

In the fifth example, the reference time signals in the video decoders561 through 581 are corrected using the APTS detected by the audiodecoder 541. The pictures can be reproduced in synchronization in asimilar manner by using one of the video decoders shown in FIG. 73 inthe fourth example and correcting the reference time signals of theother video decoders using the VPTS detected by the one video decoder.

Example 6

The sixth example relates to a reproduction apparatus for simultaneouslyreproducing two compression video signals. The two compression videosignals are obtained by dividing a signal into a right-eye video signaland a left-eye video signal and compressing the divided video signals.

The overall structure of the apparatus is generally similar to that ofthe optical disk reproduction apparatus shown in FIG. 75 in the fifthexample, but the reproduction apparatus in the sixth example includestwo video decoders for extending compression video signals obtainedafter the division means 505 since two video signals are to bereproduced simultaneously. FIG. 77 shows a structure of one of the videodecoders used in the sixth example, and FIG. 78 shows a structure of theother video decoder used in the sixth example.

As shown in FIG. 77, the video decoder includes VPTS detection means1001 for detecting a VPTS indicating the reproduction time of the videosignal multiplexed as the compression video signal, video extensionmeans 1002 for extending the MPEG compression video stream, referencetime signal generation means 1004 for generating a reference timesignal, and video reproduction timing control means 1003 for comparingthe reference time signal and the VPTS and skipping or repeating thevideo reproduction on a frame-by-frame basis when the comparison resultexceeds the threshold value and also for outputting a horizontalsynchronization signal and a vertical synchronization signal for thepicture reproduced.

As shown in FIG. 78, the other video decoder includes VPTS detectionmeans 1101 for detecting a VPTS indicating the reproduction time of thevideo signal multiplexed as the compression video signal, videoextension means 1102 for extending the MPEG compression video stream,reference time signal generation means 1104 for generating a referencetime signal, and video reproduction timing control means 1003 forcomparing the reference time signal and the VPTS and skipping orrepeating the video reproduction on a frame-by-frame basis when thecomparison result exceeds the threshold value, for outputting ahorizontal synchronization signal and a vertical synchronization signalfor the picture reproduced, and also reproducing the extended videosignal in synchronization with the horizontal/vertical synchronizationsignals.

The video decoders are connected to each other so that the horizontalsynchronization signal and the vertical synchronization signal outputfrom the video decoder in FIG. 77 are sent to the video decoder in FIG.78.

In the optical disk reproduction apparatus in the sixth example havingthe above-described structure, the reference time signal generated byeach video decoder is corrected with an APTS, and the video reproductiontiming control means of each video decoder maintains the differencebetween each reference time signal and each VPTS to be equal to or lessthan the threshold value. Thus, the right-eye picture and the left-eyepicture can be synchronized with one another on a frame-by-frame basis.By using the horizontal and vertical synchronization signals output byone of the video decoder as the horizontal and the verticalsynchronization signals of the other video decoder, two pictures can bereproduced in synchronization on a pixel-by-pixel basis.

In the sixth example, compression video signals obtained from a 3D videosignal are used and divided into the right-eye and left-eye signals.Alternatively, for example, an original video signal having a firstresolution is divided in a vertical and/or horizontal direction into atleast two video signals including a first video signal and a secondvideo signal having a second resolution which is lower than the firstresolution. The resultant signals are compressed to be used. Thus, aplurality of video signals in synchronization with one another on apixel-by-pixel basis can be obtained as from a 3D video signal. Bysynthesizing such resultant signals, the clear original video signalhaving the original resolution is reproduced.

Example 7

The seventh example relates to an optical disk reproduction apparatusfor extending one compression video signal and two compression audiosignals and reproducing the signals simultaneously.

FIG. 81 shows a data structure of the optical disk used in the seventhexample.

Two audio signals D and E are compressed to obtain compression audiostreams D and E. A video signal is compressed to obtain a compressionvideo stream.

The compression audio streams D and E and the compression video streamare packeted in units of 2 kB into audio packets and video packets. Apacket header of each packet includes a stream ID for indicating whichof the compression audio streams D and E and the compression videostream is stored, and the APTS and VPTS.

FIG. 79 is a block diagram of the reproduction apparatus in the sixthexample.

The reproduction apparatus has a generally similar structure to that inFIG. 68. The audio decoder 541 has the same structure as that shown inFIG. 69, and the video decoder 531 has the same structure as that shownin FIG. 65. The audio decoder 591 has the same structure as that shownin FIG. 80.

Reference numeral 590 represents a buffer memory for temporarily storingthe compression audio signal like the buffer memory 540. Referencenumeral 592 represents a speaker for reproducing the audio signal.

FIG. 80 shows a structure of the audio decoder 591. The audio decoder509 includes APTS detection means 1201 for detecting an APTS stored in apacket header of the audio packet, audio extension means 1202 forextending the compression audio stream, and audio reproduction timingcontrol means 1203 for comparing the reference time signal and the APTSand skipping or repeating the audio reproduction on an audioframe-by-audio frame basis when the comparison result exceeds thethreshold value.

A reproduction operation in the seventh example will be described.

The operation until the signal read from the optical disk 501 is inputto the division means 505 is similar to that in the other examples.

The data read from the buffer memory 504 is divided by the divisionmeans 505 into a compression video signal, the compression audio signalD and the compression audio signal E, and output. The division means 505identifies which of the compression video signal, the compression audiosignal D and the compression audio signal E is stored in each packetwith the packet ID in the packet header of the packeted data, anddetermines the destination based on the identification result.

The divided compression video signal, the compression audio signal D andcompression audio signal are temporarily stored in buffer memories 530,540 and 590 respectively.

The video decoders reads data from the buffer memory 530, extends thecompression video signal and outputs the signal as a video signal to amonitor 532. The audio decoders 541 and 591 read data from the buffermemories 540 and 590, extend the compression audio signals and outputthe signals as audio signals through the speakers 542 and 592.

The reference time signal generated by the reference time signalgeneration means 506 is corrected by an APTS#D detected by the audiodecoder 541.

In the audio decoder 591, an APTS#E is detected by the APTS detectionmeans 1201 and the compression audio signal E is extended by the audioextension means 1202. The audio reproduction timing control means 1203receives the extended audio signal output from the audio extension means1202, the reference time signal, and the APTS#E from the APTS detectionmeans 1201, compares the reference time signal and the APTS#E. When thedifference between the reference time signal and the APTS#E exceeds thethreshold value, the audio reproduction timing control means 1203controls the audio reproduction timing so that the difference is equalto or less than the threshold value.

In the seventh example, 32 msec is used as the threshold value. Thevideo reproduction timing control means 1203 performs the following.

(reference time signal-APTS#E)>32 msec.:1 audio frame is skipped.

(reference time signal-APTS#E)<−32 msec.:1 audio frame is repeated.

The operation of the video decoder 531 for extending the compressionvideo signal and correction performed when the difference between thereference time signal and the VPTS exceeds the threshold value aresimilar to those in the second example.

In the seventh example, due to the precision error of the crystaloscillator used in the reference time signal generation means 506, thevideo decoder 531, and the audio decoders 541 and 591; the audiodecoders 541 and 591 are slower and the video decoder 531 is faster interms of extension and reproduction with respect to the reference timesignal. Unless reproduction timing is corrected, the reproduced videosignals are out of synchronization.

FIG. 82 is a timing diagram of video reproduction in the seventhexample. Part (a) of FIG. 82 shows the APTS#D with respect toreproduction time t. Part (b) shows the reference time signal, part (c)shows APTS#E, at which the compression audio signal E to be extended bythe audio decoder 531 is to be reproduced, and part (d) shows the VPTS,at the compression video signal to be extended by the video decoder 531is to be reproduced. The reference time signal is corrected using theAPTS#D when APTS#D shows ta3 and ta4. The reference time signal is resetto ta3 and ta4 at the respective time.

The audio decoder 591 continues extension and reproduction of thecompression audio signal E, and the difference between the VPTS#E andthe reference time signal exceeds 32 msec. as the threshold value atT10. Accordingly, the video reproduction timing control means 1203 ofthe audio decoder 591 skips one audio frame which is originally to bereproduced to correct the reproduction timing so that the differencebetween the VPTS#E and the reference time signal is equal to or lessthan the threshold value.

The difference between the VPTS and the reference time signal exceeds−33 msec. as the threshold value at T11 and T12. Accordingly, the videoreproduction timing control means of the video decoder 531 reproducesone frame in repetition which has been already reproduced at therespective time to correct the reproduction timing so that thedifference between the VPTS and the reference time signal is equal to orless than the threshold value.

As described above, in the seventh example, when the difference betweenthe reference time signal and the VPTS#E detected by the audio decoder591 exceeds the threshold value, the video reproduction timing controlmeans of the audio decoder performs correction so that differencebetween the reference time signal and the APTS#E does not exceed thethreshold value. In this manner, each audio signal and the picture canbe synchronized with one another.

Example 8

In the eighth example, the clock for performing extension is changed foraudio reproduction control.

The overall structure and operation of the reproduction apparatus in theeighth example are generally similar to those of the optical diskreproduction apparatus in the seventh example, but the operation ofaudio reproduction timing control performed when the reference timesignal and the APTS#E exceeds the threshold value is different from thatof the seventh example. With reference to FIGS. 83 and 84, audioreproduction timing control used in the eighth example will bedescribed.

FIG. 83 shows an operation when the difference between the APTS#E andthe reference timing signal exceeds 32 msec. which is the threshold forthe audio reproduction. Part (a) of FIG. 83 shows the reference timesignal with respect to reproduction time t. Part (b) shows the APTS#E,and part (c) shows the clock frequency at which the audio decoder 591performs extension and reproduction. Ordinary extension and reproductionare performed by clock f0 having a frequency which is 384 times thesampling frequency fs of the audio signal. The difference between theAPTS#E and the reference time signal exceeds 32 msec. at time T11, andaccordingly, audio reproduction control means switches the clock f0 tof1. The frequency of clock f1 is higher by 10% than the frequency ofclock f0. Extension performed with clock f1 proceeds faster thanextension performed with clock f0 by 10%. With clock f1, the extensionis performed for 320 msec. from the point where the difference betweenthe APTS#E and the reference time signal exceeds 32 msec. which is thethreshold value. Thus, the reproduction timing is corrected so that thedifference between the APTS#E and the reference time signal is equal toor less than the threshold value.

FIG. 84 shows an operation when the difference between the APTS#E andthe reference timing signal exceeds −32 msec. which is the threshold forthe audio reproduction. Part (a) of FIG. 83 shows the reference timesignal with respect to reproduction time t. Part (b) shows the APTS#E,and part (c) shows the clock frequency at which the audio decoder 591performs extension and reproduction.

The difference between the APTS#E and the reference time signal exceeds−32 msec. at time T12, and accordingly, audio reproduction control meansswitches the clock f0 to f2. The frequency of clock f2 is lower by 10%than the frequency of clock f0. Extension performed with clock f2proceeds more slowly than extension performed with clock f0 by 10%. Withclock f2, the extension is performed for 320 msec. from the point wherethe difference between the APTS#E and the reference time signal exceeds−32 msec. which is the threshold value. Thus, the reproduction timing iscorrected so that the difference between the APTS#E and the referencetime signal is equal to or less than the threshold value.

As described above, when the difference between the APTS#E and thereference time signal exceeds the threshold value for the audioreproduction, the clock by which the signal is extended is changed sothat the extension is performed at a higher speed or lower speed thanthe normal speed. By such an operation, the reproduction timing iscontrolled so that the difference between the APTS#E and the referencetime signal is equal to or less than the threshold value. Thus, theaudio signals and the video signal can be reproduced in synchronizationwith no unnaturalness in the audio output.

In the eighth example, the frequency of the clock is changed by 10%.Needless to say, a more natural audio signal is obtained by reducing theclock less or gradually.

In the seventh and eighth examples, the reference time signal iscorrected using the APTS#D. Alternatively, the video decoder shown inFIG. 73 can be used, in which case the VPTS output from the videodecoder can be used for correction.

The present invention has been described by way of specific examples.

The comparison between the reference time signal and the VPTS or APTS,control of the reproduction time, correction of the reproduction timingcan be performed by a microcomputer which controls the entirety of thereproduction apparatus.

In the above examples, the present invention is applied to optical diskreproduction devices. The present invention is also applicable to areproduction apparatus for extending signals supplied throughcommunication networks and digital satellite broadcasting as compressionsignals.

INDUSTRIAL APPLICABILITY

A basic video signal and an interpolation signal are divided into frameseach having 1 GOP or more and subjected to interleaving alternately tobe recorded on the optical disk as interleave blocks 54 and 55; Fromsuch an optical disk, a progressive/3D reproduction apparatus reproducesboth information in the interleave block for the odd field (right eye)and information in the interleave block for the even field (left eye).Thus, a progressive/3D picture is obtained. A non-progressive/3Dreproduction apparatus reproduces information in the interleave block ofonly odd field (right eye) or even field (left eye) by track jump. Thus,a complete two-dimensional picture is obtained. Thus, compatibility isrealized.

Especially, a progressive/3D picture arrangement information file and aprogressive/3D picture identifier are recorded on the optical disk.Accordingly, the location of the progressive/3D is easily determined.Therefore, two ordinary interlace signals can be made into a progressivesignal. Furthermore, it can be avoided that pictures for the right eyeand left eye of different contents are output on the 3D TV.

In a 3D reproduction apparatus, a pointer used for two-dimensionaldisplay is used when an 3D identifier is available to change the accessprocess. Thus, 3D pictures can be continuously displayed. Moreover, a 3Dreproduction apparatus is realized without changing the two-dimensionalformat.

According to the synchronization method of the present invention, aplurality of video signals or a plurality of audio signals to besimultaneously reproduced are extended in synchronization forreproduction.

In the embodiment where a horizontal synchronization signal and avertical synchronization signal which are output from one video decoderare used as the horizontal synchronization signal and the verticalsynchronization signal of another video decoder, synchronization on apixel-by-pixel basis is realized even when, for example, a plurality ofcompression video signals are extended and the extended signals aresynthesized into a 3D picture or a high resolution picture.

In a reproduction apparatus in which the reference time signal iscorrected using an APTS detected by an audio decoder and the videooutput timing is controlled so that the VPTS matches the correctedreference time signal, an audio signal and a plurality of video signalsare synchronized for reproduction with no unnaturalness in the audiooutput.

In a reproduction apparatus in which the audio output timing iscontrolled by changing an extension clock, audio and video signals aresynchronized for reproduction with no unnaturalness in the audio outputwith no interruption or pause in the audio signal.

The invention claimed is:
 1. A decoding method for decoding a codeddata, said method comprising the steps of: receiving the coded datahaving i) a broadcast program having a coded sequence which includes a)a coded stereoscopic image which is encoded from a stereoscopic image,b) a coded non-stereoscopic image which is encoded from anon-stereoscopic image, c) first identification information included ineach coded image which indicates whether the coded image is the codedstereoscopic image or the coded non-stereoscopic image, and d) secondidentification information which indicates whether the coded imageincludes a progressive image, and ii) broadcast program informationseparate from the broadcast program, the broadcast program informationcomprising an arrangement table which indicates whether sets of codedimages in the broadcast program include a stereoscopic content or not,outputting a signal to inform a decoding broadcast program includes thestereoscopic content, when the broadcast program information indicatesthe decoding broadcast program includes the stereoscopic content,decoding the coded stereoscopic image and outputting the stereoscopicimage, when the identification information indicates that the codedimage is the coded stereoscopic image, and decoding the codednon-stereoscopic image and outputting alternately two field images whichconsist of the non-stereoscopic image, when the first identificationinformation indicates that the coded image is the coded non-stereoscopicimage and the second identification information indicates that the codedimage is not the progressive image, wherein the coded stereoscopic imageincludes a third coded image which is encoded from a stereoscopic rightimage of the stereoscopic image and a fourth coded image which isencoded from a stereoscopic left image, the third coded image isdifferent from the coded non-stereoscopic image, and the fourth codedimage is different from the coded non-stereoscopic image.